Template:Sidebar character

For the mirror universe counterpart, please see Miles O'Brien (mirror).
For the replicant O'Brien, see Miles O'Brien (replicant).

Miles Edward O'Brien was born in Ireland, Earth in September 2328. (DS9: "Homefront", "Whispers")

Following his service during the Federation-Cardassian War, he was stationed aboard the USS Enterprise-D and served as transporter chief for several years. He later jumped at the opportunity when he was offered a promotion to Chief of Operations aboard starbase Deep Space 9, although the switch did not sit as well with his wife Keiko. Together, Miles and Keiko had two children, Molly and Kirayoshi. The Dominion War nearly tore the family apart, however, and when it had finished, Miles was happy to accept a teaching position at Starfleet Academy on Earth.

Early life

O'Brien traced his ancestry back to the 11th century Irish king Brian Boru (whom he occasionally played in a holosuite program). Another notable O'Brien ancestor was Sean Aloysius O'Brien. (DS9: "Bar Association")

O'Brien was raised on real food; his mother believed that replicated food was less nutritious. She even handled and cut actual meat. (TNG: "The Wounded")

O'Brien had two brothers, and three sisters. His mother passed away in 2368 and his father, Michael, remarried a year later, though Miles had never met his new stepmother. (DS9: "Whispers") His relationship with his father had been a somewhat rocky one during Miles' adolescence; Michael was the one who had pushed Miles to pursue his music career, making him practice at least once a day, and was somewhat upset by his son's enlistment in Starfleet. The two later reconciled, however, and the elder O'Brien was eventually extremely proud of his son and his accomplishments. (DS9: "Shadowplay")

As a child, O'Brien had a morbid fear of spiders. Following a mission on Zayra IV where O'Brien was forced to make a critical repair in a Jefferies tube containing Talarian hook spiders, he found that his fear had lessened, and he later kept a Lycosa tarantula, named Christina, as a pet aboard the Enterprise-D. (TNG: "Realm of Fear")


In 2346, at the age of 18, O'Brien joined Starfleet as an enlisted crewman. His father had wanted Miles to take up a place at the Aldebaran Music Academy and become a concert cellist, but he chose a life in Starfleet instead. (DS9: "Shadowplay")

Assignment aboard the Rutledge


One of his first assignments was aboard the USS Rutledge, under the command of Benjamin Maxwell, where he served as junior tactical officer during the Cardassian War. A year later, O'Brien was present at the aftermath of the Setlik III massacre, where his technical skill was useful in repairing a field transporter, allowing himself and thirteen other Starfleet personnel to escape a Cardassian patrol. This earned him a promotion to primary tactical officer. O'Brien also served as part of a squad to aid the survivors of the massacre as Cardassians were still patrolling the settlement; he helped a group of women and children but was ambushed by two Cardassians. He was able to incapacitate one of them but he got into a fight with the other and accidentally killed his assailant when a Phaser passed to him was set to maximum. Until then, O'Brien had never killed anything or anyone (he was even worried about swatting mosquitoes as a child) and the incident left him with a deep-seated resentment towards Cardassians, bordering on outright racism on occasion. He often referred to them by the derogatory term "Cardies". (DS9: "Emissary", "Captive Pursuit", "The Homecoming", "The Siege", "Tribunal") Many years later, he remarked to Glinn Daro that it was not Cardassians that he hated, but rather the person he became because of them. (TNG: "The Wounded")

Assignment aboard the Enterprise-D

Miles O'Brien, 2367

Miles O'Brien in 2367.

O'Brien transferred to the USS Enterprise-D in 2364, with the rank of chief petty officer, under the command of Captain Jean-Luc Picard. During the Farpoint Mission he was assigned as relief flight controller. He also stood duty in the security department, but was most often seen filling duty as transporter chief, where he was involved in, among other events, the rescue of Captain Picard from the Borg in 2367. (TNG: "Encounter at Farpoint", "All Good Things...", "Lonely Among Us", "Unnatural Selection", "The Best of Both Worlds, Part II")

In all episodes of TNG Seasons 2-5, O'Brien is seen wearing the insignia of a full lieutenant while working as transporter chief; in one of them, "Where Silence Has Lease", he is also addressed as "lieutenant".

In 2367, Miles was forced to confront his former commanding officer, when Captain Maxwell went rogue, launching attacks on Cardassian outposts and ships in spite of a peace treaty between the Federation and Cardassia. It was O'Brien's knowledge of transporter systems that allowed him to beam aboard Maxwell's ship, the Phoenix, while her shields were up, giving him a chance to reason with Maxwell, ultimately preventing further bloodshed. (TNG: "The Wounded")

During the Klingon Civil War, O'Brien also made use of his training as a tactical officer, following Lieutenant Worf's resignation from Starfleet. As a result, he was heavily involved in the deployment and maintenance of the tachyon detection grid that ultimately decided the conflict. (TNG: "Redemption II")

In 2368, Miles, along with Deanna Troi and Data, was taken over by an alien life-form, which forced them to take hostages to use as a bargaining chip in negotiating with Picard. Among the prisoners were Molly and Keiko O'Brien. Eventually, the life-form left when it was discovered that the moon was actually a 'penal colony' and that this was an attempt to escape. (TNG: "Power Play")

Assignment aboard Deep Space 9

File:Miles O'Brien.jpg

By 2369, O'Brien had been operating transporters for 22 years. In that year, O'Brien left the Enterprise, transferring to Deep Space 9 with a promotion, assigned the role of chief of operations. His primary task during the early days of his posting was to repair the damage done during the withdrawal of the Cardassians from the station. He was instrumental in moving the station from its orbit of Bajor out to the Denorios belt, following the discovery of the Bajoran wormhole. (DS9: "Emissary")

Not long after, O'Brien received a note on his record for violating the Prime Directive, after assisting in the escape of a Tosk, one of the first contacts from the Gamma Quadrant, disobeying direct orders from Commander Sisko. Tosk was a being raised to be the prey in a hunt by those known as the Hunters. (DS9: "Captive Pursuit")

He later found himself entangled in local Bajoran politics and folklore when visiting a remote village on the planet. Following the death of the local sirah, O'Brien was thrust into the role, forcing him to try and maintain the unity and strength of the inhabitants against a Dal Rok. (DS9: "The Storyteller")

In 2369, O'Brien's assistant Neela attempted to assassinate Vedek Bareil. O'Brien discovered the plot and informed Sisko just in time to save Bareil's life. (DS9: "In the Hands of the Prophets")

He assisted Kira Nerys in rescuing Li Nalas from a Cardassian labor camp, and defended the station against the Circle, a Bajoran terrorist group who wanted the Federation to leave the sector. (DS9: "The Homecoming", "The Circle", "The Siege")

In 2370, O'Brien was assisting the T'Lani and Kellerun militaries in disarming and neutralizing their harvester weapons when a sabotage attempt exposed him to deadly nanobiogenic gel. In the resultant escape and rescue, he almost succumbed to his injuries, but was saved by Julian Bashir, an act which developed their friendship (see Personal, below). Several months later, while assisting in preparations for a Parada peace conference on Parada II, O'Brien was kidnapped and replaced with a replicant, created to disrupt the conference. That duplicate O'Brien later died after others became aware of the threat he posed, and the real O'Brien was recovered by DS9 personnel. (DS9: "Armageddon Game", "Whispers")

Later in 2370, Quark tried to use Bashir and O'Brien in a racquetball scam. He had fixed the game in O'Brien's favor and with everyone betting on Bashir, intended to clean up. O'Brien became stranded on an Earth colony with Sisko, where an energy dampening field made it impossible to communicate with the orbiting runabout to leave the planet. O'Brien found out that it was an artificial field and was able to turn it off. (DS9: "Rivals", "Paradise")

In December of that year, O'Brien was arrested by Cardassian forces and put on trial for allegedly supplying weapons to the Maquis, based on, among other evidence, a falsified voiceprint. The charges were later discovered to be part of a conspiracy to discredit the Federation and give the Cardassian Union a stronger position from which to negotiate, and O'Brien was released. (DS9: "Tribunal")

In 2371 O'Brien helped disable a self-destruct mechanism on the station left by the Cardassians. He helped rescue Sisko from the past, and also worked with a group of female Cardassians on a science project on the station. One of the scientists wanted to become romantically involved with him, but he refused. (DS9: "Civil Defense", "Past Tense, Part II", "Destiny")

O'Brien was killed later in 2371, after becoming infected with delta-series radioisotopes following an accident aboard the station. This, coupled with the presence of a cloaked Romulan Warbird nearby, had the effect of shifting him forward in time by several hours. His death occurred when he deliberately contaminated himself further in order to determine the exact cause of events he had witnessed. He was 'replaced' by his counterpart from the timeline he visited. Thus, events that occurred to O'Brien from this point on involved the future version, rather than the 'original'. (DS9: "Visionary")

Obrien defends with phaser

O'Brien defends his post

When the Klingons attacked and invaded Deep Space 9 in January of 2372, O'Brien defended Ops against boarding parties, suffering minor injuries in the attack. At the time of the attack, O'Brien had been completing the retrofit of the station's weapons arrays. (DS9: "The Way of the Warrior")

His image was accidentally used in a holo-program by Julian Bashir and Garak when a runabout he was on was destroyed by Cardassian terrorists. The computer, under direction of Michael Eddington, stored his physical image in the open holosuite program (as the evil assassin Falcon) while his conscious mind was stored in DS9's computer core. (DS9: "Our Man Bashir")

Later that year, Miles was temporarily relieved of his duties by Captain Sisko, following a visit to the planet Argratha. O'Brien had been (falsely) accused of espionage, and was given the simulated memory of a 20-year prison sentence. O'Brien became paranoid and emotionally distressed upon returning to the station, attempting suicide on at least one occasion. (DS9: "Hard Time")

In late 2372, O'Brien commented that his career had included service on half a dozen ships. Even though none of those vessels had cloaking devices, O'Brien was so used to the Defiant being cloaked that he felt vulnerable aboard uncloaked ships.

He took part in the joint effort between the Federation and Jem'Hadar to track down a group of renegade Jem'Hadar soldiers that captured an Iconian gateway. (DS9: "To the Death")

In 2373, O'Brien took part in an infiltration mission to the fortified Klingon moon of Ty'Gokor in an attempt to expose Gowron as a Changeling. For the mission, Miles had to be surgically altered to appear Klingon. (DS9: "Apocalypse Rising")

O'Brien, as part of a Defiant away team, discovered a crashed Jem'Hadar ship on a planet. When a Vorta and a team of Jem'Hadar came to retrieve the ship, a fight broke out. A crewman O'Brien had become close to, Enrique Muñiz, also died as a result of wounds he received in battle, and this affected O'Brien deeply. (DS9: "The Ship")

While away on Bajor, Keiko became possessed by a Pah-wraith. It threatened to kill Keiko unless O'Brien helped it to blow up the wormhole. He tricked it on the way to the wormhole and shocked it to drive it out of Keiko. He also went back in time to the original Enterprise and met Captain Kirk, helping to stop a Klingon from assassinating Kirk and changing history. (DS9: "The Assignment", "Trials and Tribble-ations")

On an assignment to Empok Nor to get a part necessary for the station, he and his team found two Cardassians in stasis. Upon waking, they murdered some of the team before Garak killed one of them. Garak became infected with a drug in the Cardassians' systems and turned into an insane murderer, killing the other soldier and one of O'Brien's crew before O'Brien was able to disable him and return him to the station for treatment. (DS9: "Empok Nor")

Service during the Dominion War

O'Brien was partly responsible, along with Rom and Jadzia Dax, for creating and deploying the self-replicating minefield that blocked Dominion ships from entering the Alpha Quadrant, an event which precipitated the Dominion War. Miles abandoned the station with the rest of the station's Starfleet complement, taking station aboard the Defiant, where he remained for the first three months of the war. (DS9: "Call to Arms")

Along with the rest of the DS9 command crew, O'Brien was pulled from front-line duty to take a captured Jem'Hadar vessel behind enemy lines. Despite his love of field rations, O'Brien bemoaned the lack of a replicator aboard the commandeered vessel. When the vessel crash-landed shortly after achieving its objective, O'Brien tore his uniform, much to his chagrin and the amusement of his colleagues. (DS9: "A Time to Stand")

He was part of the away team that confronted the Jem'Hadar on a planet after both sides crashed. The Jem'Hadar were betrayed by their Vorta and led into an ambush. The Vorta was about to run out of ketracel-white and feared the Jem'Hadar would kill him. (DS9: "Rocks and Shoals")

Following their rescue by the Rotarran, Miles took part in Operation Return, which successfully recaptured the station. He resumed his duties aboard the newly-retaken Deep Space 9. Shortly thereafter, he played a ceremonial role in the wedding of Jadzia Dax and Worf. (DS9: "Sacrifice of Angels", "You Are Cordially Invited")

Miles O'Brien undercover

O'Brien with his contact person from Starfleet Intelligence during a covert mission on Farius Prime in 2374.

In mid-2374, O'Brien was recruited by Starfleet Intelligence to infiltrate the Orion Syndicate arm on Farius Prime. During the mission, Miles grew friendly with Liam Bilby, a Syndicate operative. After Bilby was killed attempting to assassinate the Klingon ambassador, O'Brien took in his cat, Chester, as a family pet, and paid money into an account for his wife. (DS9: "Honor Among Thieves")

He helped rescue the Defiant after it had been taken over by the Jem'Hadar. His daughter fell into a time portal placing her 300 years in the past. Upon being rescued, she was a teenager who had lived her life in a prehistoric era. She was unable to cope, and when returned into the portal found herself as an eight year old, where she helped guide herself back to her parents. (DS9: "One Little Ship", "Time's Orphan")

Following the death of Jadzia Dax at the end of 2374, O'Brien took part in the Rotarran's successful assault on the Monac shipyards, a mission intended by Worf to get his wife into Sto-vo-kor. (DS9: "Shadows and Symbols")

Later in 2375, Miles disappeared on New Sydney while attempting to track down Morica Bilby, Liam's wife, who had disappeared from her home on the planet. O'Brien's mission was unauthorized, and he received a reprimand as a result. (DS9: "Prodigal Daughter")

Shortly before the final battle of the war, O'Brien took part in the attempt to restore Vic Fontaine's casino. It had been taken over by Chicago gangsters. (DS9: "Badda-Bing, Badda-Bang")

Shortly before the end of the war, O'Brien accepted a position at Starfleet Academy as a professor of engineering. Following the Battle of Cardassia, O'Brien departed Deep Space 9 for Earth, to take up this new role. Immediately prior to leaving, he was still considering where exactly his family would settle on Earth. His crewmates all gave suggestions: Worf was particularly insistent he look at Minsk. (DS9: "What You Leave Behind")

As of Stardate 49648.0, O'Brien had served aboard a half dozen starships, participated in 232 separate combat engagements, and had been decorated by Starfleet on fifteen occasions. (DS9: "Rules of Engagement", "Broken Link")



He married Keiko Ishikawa aboard the Enterprise on October 24th, 2367, and the couple had their first child, Molly, the following year. (TNG: "Data's Day", "Disaster") Both joined O'Brien aboard DS9, albeit reluctantly on Keiko's part, where their second child, Kirayoshi, was born in 2373. O'Brien had a difficult time dealing with this pregnancy, mainly as a result of the baby's forced 'relocation' to Kira Nerys in late 2372, which saw the two struggling with a mutual attraction – one which both agreed to put aside. (DS9: "Body Parts", "Looking for par'Mach in All the Wrong Places", "The Begotten")

As a ritual before going into battle, O'Brien recorded a "goodbye" message for his family in the event of his death. Each time he did so, he believed it would be the one they would hear. Between 2367 and 2372, he had recorded a total of eleven messages. (DS9: "To the Death")


Julian Bashir

Obrien and Bashir drunk

O'Brien and Bashir sing Jerusalem together

Aboard Deep Space 9, O'Brien forged a strong friendship with Julian Bashir, the station's Chief Medical Officer. Initially, Miles took a strong dislike to the young doctor: he considered him arrogant and too talkative. Mutual respect developed when the two had to work together to survive on T'Lani III. When the two thought they were about to be killed, O'Brien admitted it was an honor to serve under the Doctor. (DS9: "The Storyteller", "Armageddon Game")

A friendly rivalry developed between the two in racquetball, darts, and other activities. The two were frequent users of the station's holosuites, usually for historical reenactments of events such as the Battle of Britain, Battle of Clontarf and even created their own programs, including an accurate depiction of the Alamo. (DS9: "Rivals", "Visionary", "Accession", "Bar Association", "The Changing Face of Evil" et. al)

Their friendship grew so close that Miles considered Julian as important to him as his wife. While drinking and trying to cheer up Julian about not being noticed by his Academy rival, Elizabeth Lense, O'Brien came close to admitting that he loved Bashir. On another occasion, Miles inadvertently expressed the wish that Keiko was more like Julian. However, Miles was eventually able to accept that he could be close to both his friend and his wife. (DS9: "Explorers", "Hippocratic Oath", "Extreme Measures")

The friendship was strained at times. When Julian and Miles were trapped on a planet with some rogue Jem'Hadar, Bashir decided to help their leader Goran'Agar find out why he was no longer addicted to the white. Miles was vehemently against such a proposal, noting that the Jem'Hadar were enemies of the Federation, and that freeing them of the white would make them a larger threat to the Alpha Quadrant. He was further resentful when Bashir ordered him to help. On another occasion, Bashir and a group of genetically engineered Humans predicted that the Federation was doomed to lose the Dominion War. Miles was angry at the sheer arrogance shown by the group, noting that they were not as smart as they thought they were. (DS9: "Hippocratic Oath", "Statistical Probabilities")

The friendship helped the two through troubled times. When O'Brien was given twenty years of prison memories for a crime he did not commit by the Argrathi and could not adjust, he attempted to kill himself. One of the false memories was that he had killed his best friend in prison, even admitting that had it been Bashir in the cell with him, he would have killed the doctor as well. It was Bashir who was able to talk him out of the attempt and get him help. (DS9: "Hard Time") Later, as Bashir became desperate to find a cure for Odo's morphogenic virus, O'Brien came up with the scheme to lure a Section 31 operative onto the station, capture him, and then probe his mind for knowledge of the cure. Then, when Bashir decided to delve into Luther Sloan's dying mind for the knowledge, O'Brien insisted on going with him, which proved critical in keeping Bashir focused on obtaining the cure. (DS9: "Tacking Into the Wind", "Extreme Measures")



Miles O'Brien and Worf knew each other from their early days on the Enterprise, although their relationship was that of a noncom and his superior. The two would, however, play together in the crew's poker games. O'Brien participated in Wesley Crusher's Age of Ascension recreation for Worf, where he commented on the power of the Klingon painstiks. (TNG: "The Emissary", "The Icarus Factor")

O'Brien was the first person, besides Worf, to greet the Klingon's adoptive Human parents, upon their arrival on board the Enterprise. (TNG: "Family")

Although Worf had to man the bridge at O'Brien's wedding to Keiko, he gave O'Brien a Klingon weapon as a wedding gift. In 2368, when the Enterprise was damaged by a quantum filament, Worf was forced to deliver Keiko's baby daughter, Molly. He humorously noted that Molly resembled Miles. (TNG: "Data's Day", "Disaster")

OBrien and Worf

O'Brien and Worf on board DS9

The friendship strengthened when Worf transferred to Deep Space 9. O'Brien was the first person to greet Worf when he arrived. Later he introduced Worf to the game of darts, describing it as "poker, but with pointed tips." Once Worf accepted the role of strategic operations officer (with a change of uniform from yellow to red), O'Brien commented how good Worf looked in red. (DS9: "The Way of the Warrior")

When the Defiant was damaged by the Jem'Hadar during their Karemma negotiations, and Worf found commanding the engineering team difficult, O'Brien helped Worf take a different approach to command. (DS9: "Starship Down")

When Worf discovered that the O'Briens were having another child, he altered his holiday plans to coincide with the birth, just so he wouldn't have to deliver O'Brien's baby (like he did with Molly). (DS9: "Accession")

During Worf's trial that demanded his extradition to the Klingon Empire, O'Brien described Worf as "an honorable man". In turn, Worf described O'Brien as an "outstanding officer" and a friend, relaying their mutual respect out loud. (DS9: "Rules of Engagement")

Worf incited a riot against the Jem'Hadar, Toman'torax, in retaliation for threatening O'Brien. (DS9: "To the Death")

In 2373, Worf and O'Brien participated in recovering a Jem'Hadar ship from Torga IV. Although Worf believed that Enrique Muñiz would not survive from his wounds, O'Brien did not agree and clashed with Worf's pessimism. Worf was later proved right however, and Muñiz did pass away. Once the mission was over, O'Brien and Worf performed the Klingon tradition of ak'voh in front of Muñiz's casket. (DS9: "The Ship")

O'Brien had to undergo a ritual fasting with Julian Bashir and Sisko as part of Worf's Kal'Hyah ceremony, which was different than what he thought it would be. He couldn't last the four days (even vowing to kill Worf at one point), and when he heard the wedding ceremony was called off, he and Bashir immediately ordered a large feast of Terran and Bajoran food. However, Sisko stopped them and helped put the wedding back on track. (DS9: "You Are Cordially Invited")

At one point, Worf and O'Brien, while watching Jadzia and Quark playing a game of tongo against each other and a group of Ferengi waiters, Worf made a bet that Jadzia had the game in hand. He wagered to O'Brien that if she won, he would owe Worf a bottle of bloodwine. If Jadzia lost, however, Worf would then owe the chief a bottle of Irish whiskey. In the end, however, Worf ended up saying that he would need time to come up with O'Brien's payment. (DS9: "Change of Heart")

After Jadzia Dax died at the hands of Gul Dukat, O'Brien was one of the first people who attempted to cheer up Worf. While drinking bloodwine and reminiscing about old crewmates (most notably, Reginald Barclay), O'Brien found out what was bothering Worf – the fact that his wife did not die an honorable death, and thus could not enter Sto-vo-kor. O'Brien then directed Martok to help Worf, who assigned him the mission to destroy the Monac IV fleet yards. (DS9: "Image in the Sand")

A short time later, O'Brien helped Worf ease his hostility to Ezri. Over a bottle of bloodwine, O'Brien asked how Jadzia would feel if she knew how poorly Worf treated Ezri. When Worf claimed that there was no way to know, O'Brien refuted the claim, suggesting he talk to the one person Worf had been avoiding. After keeping her in Starfleet, Worf and O'Brien attended Ezri's promotion party. (DS9: "Afterimage")

When O'Brien's authorization code was used to access sixteen cases of bloodwine sent to Martok by Sirella, Martok and Worf had to quiz O'Brien on where the cases went. O'Brien had to explain to Worf and Martok that Nog must have taken the bloodwine to barter for a graviton stabilizer. Worf and Martok gave O'Brien one day to find the bloodwine. Fortunately, Nog had returned with 16 cases of 2309 bloodwine bought from his cousin Gant, an even better vintage than the ones Nog took. Both Klingons gave O'Brien a bottle of the bloodwine as an "apology". (DS9: "Treachery, Faith and the Great River")

Benjamin Sisko

O'Brien's relationship with Benjamin Sisko could be described as a classic example of a crewman's loyalty and devotion to a commander. And this relationship developed quickly. O'Brien respected Sisko from the first, and Sisko came to rely on Miles to keep Deep Space Nine running in the earliest days of his command.

Sisko was quick to reprimand O'Brien, after the Tosk incident (DS9: "Captive Pursuit"), even though he approved of O'Brien's actions on a personal level.

Aside from this incident, Sisko seemed to have a very casual relationship with O'Brien, despite the difference in their ranks and the fact that Miles was an enlisted crewman and Sisko an officer. And O'Brien was unswervingly loyal to his commander.

O'Brien volunteered to remain behind on Deep Space Nine to help Sisko, Li Nalas, and a handful of others retain control of the station after Starfleet was ordered off by the Provisional Government, under the influence of The Circle. He did this even though it could have meant the end of his Starfleet career and over the strenuous objections of his wife.(DS9: "The Siege")

Kira Nerys

O'Brien's relationship with the Bajoran first officer of Deep Space Nine started out rocky. Kira did not trust Starfleet, or the presence of the Federation on DS9. But, O'Brien earned her trust, and her friendship.

The turning point in O'Brien's relationship with Kira came when he helped her rescue Li Nalas from a Cardassian prison camp. From this point, Kira began to view O'Brien as someone she could trust, and someone she could rely on in a dangerous situation (DS9: "The Homecoming").

Kira carried Miles and Keiko O'Brien's baby to term following a runabout accident that threatened Keiko's pregnancy. The fetus was transferred to Kira's womb under the emergency circumstances so that both mother and child might live. During Kira's pregnancy, she and Miles formed a close, even intimate personal relationship. Kira was invited by Keiko to live in the O'Briens' quarters, and Miles helped Kira with the pregnancy's physical discomfort with massages and other Bajoran treatments. The physical and emotional closeness of this time caused O'Brien and Kira to struggle against romantic feelings that developed between them. (DS9: "Body Parts", "Looking for par'Mach in All the Wrong Places")


During his childhood, Miles developed keen construction skills. Despite doing poorly in mechanical aptitude tests, he spent many hours constructing model starship engines, models of subspace transceiver assemblies, and ships in a bottle. He also did a great deal of hiking, climbing mountains in his native Ireland. (TNG: "Booby Trap", "All Good Things...")

O'Brien's one continuing passion was kayaking, and he frequently found himself visiting sickbay or the infirmary for shoulder injuries sustained during programs. (TNG: "Transfigurations",DS9: "Shakaar", "Inquisition") This eventually resulted in humeral socket replacement surgery in 2371 (although the injury that necessitated the operation was not sustained through the sport). This did not end O'Brien's shoulder problems – he suffered a torn rotator cuff four years later, while practicing baseball with the Niners. (DS9: "Take Me Out to the Holosuite") He enjoyed singing while kayaking, which he felt helped establish a good paddling rhythm. (DS9: "Heart of Stone")

Alamo model, The changing face of evil

O'Brien created a detailed model of the Alamo in his quarters, which he left to Julian Bashir after he left for Earth in 2375.

Together with Julian Bashir, O'Brien pursued several other hobbies like racquetball, darts and historical reenactments in the holosuite of events such as the Battle of Britain, Battle of Clontarf or the defending of the Alamo, of which he even created a detailed model in his quarters. (DS9: "Rivals", "Visionary", "Accession", "Bar Association", "The Changing Face of Evil" et. al)

He maintained his love of music, playing the cello in a string quartet aboard the Enterprise. (TNG: "The Ensigns of Command", "Sarek") O'Brien was also a fan of detective fiction novels, particularly Mickey Spillane and his character Mike Hammer, a preference he passed on to Odo, to whom he frequently loaned books. (DS9: "Field of Fire")

O'Brien was literate in the Trill language. (DS9: "Prodigal Daughter")

A favored drink of O'Brien's was coffee: Jamaican blend, double-strong, double-sweet. (DS9: "Whispers")

O'Brien was a fan of Starfleet combat rations, and that those rations were the only thing that he missed about the Cardassian front. (DS9: "The Siege")

According to Sarina Douglas, she thought O'Brien would be a fitting replacement for Greek god Atlas if he ever got tired, adding that "he would do it with a smile on his face." (DS9: "Chrysalis")


Obrien as Falcon

Falcon with O'Brien's appearance

Miles O'Brien has been holographically duplicated on a number of occasions.

Alternate realities and timelines





  • Miles O'Brien was played by Colm Meaney in all appearances.
  • According to DS9 executive producer/writer Ira Steven Behr, "O'Brien is everyman. In a show about humans and aliens, he's as human as you get." Similarly, Behr's writing partner for the first four seasons of the show, Robert Hewitt Wolfe, says, "He's just a regular guy, a guy doing his job. He's just the most unlikely of all heroes because he's a family man with a daughter and eventually a son and a wife and they have arguments and a real relationship, and he's just a working class schmo, I mean obviously he's a really bright guy and very good at what he did, but basically, a working class schmo just trying to get through his day." (Crew Dossier: Miles O'Brien, DS9 Season 5 DVD, Special Features)
  • The DS9 writing staff had a running joke with a semi-annual "O'Brien Must Suffer" episode. Among these were "Whispers", "Tribunal", "Visionary", "Hard Time", "Honor Among Thieves" and "Prodigal Daughter". (Star Trek: Deep Space Nine Companion) According to Ira Behr, "Every year in one or two shows we try to make his life miserable, because you empathize with him." Robert Hewitt Wolfe further explains, "If O'Brien went through something torturous and horrible, the audience was going to feel that, in a way they wouldn't feel it with any of the other characters. Because all the other characters were sort of, I wouldn't say larger than life, but nobler than life, but O'Brien was just a guy, trying to live his life and so if you tortured him that was a story." (Crew Dossier: Miles O'Brien, DS9 Season 5 DVD, Special Features)
  • The relationship built up on DS9 between O'Brien and Bashir was very important to all of the writers, as well as both actors. According to Ronald D. Moore, after the scene where they sing Jerusalem together in DS9: "Explorers", all of the staff writers wanted to write scenes involving their friendship. Alexander Siddig says, "it's been said, by even the producers, that O'Brien and Bashir are the only real friendship that's ever happened on Star Trek. These two really are friends. It's not like some kind of odd couple scenario, like Spock and Kirk. It's a real friendship. These people talk about inane things, and I think that's been really refreshing." Robert Hewitt Wolfe elaborates, "It was just great. There was just great chemistry between the two actors, great chemistry between the two characters. It was brilliant of Michael and Rick to create these two characters as foils for each other. And to then see this relationship develop over the years till they're best friends, till Miles actually likes Bashir kind of almost better than his wife some days, which is very real, I mean there's days that everybody, you know, it's easier to be friends with a friend than with your wife some days." (Crew Dossier: Miles O'Brien, DS9 Season 5 DVD, Special Features) Ira Behr goes even further, and cites it as his favorite relationship in all of Star Trek; "The relationship between Bashir and O'Brien is the best relationship, the best friendship, in the history of the franchise. Spock and Kirk were still about the captain and his number one. This is a friendship with two equals, two guys. It's a wonderful thing to watch how this relationship has grown." (Crew Dossier: Julian Bashir, DS9 Season 6 DVD, Special Features)
  • O'Brien is one of two enlisted characters in Star Trek to have received any significant character development, the other being Yeoman Janice Rand.
  • O'Brien is one of four characters to appear in two series premieres (TNG: "Encounter at Farpoint" and DS9: "Emissary"), the others being Jean-Luc Picard, Quark, and Morn.
  • O'Brien is one of four characters to appear in two series finales, (TNG: "All Good Things..." and DS9: "What You Leave Behind") the others being Worf, William T. Riker and Deanna Troi.
  • O'Brien has worn the most versions of a Starfleet Uniform without having appeared in a film, having worn 7 versions of uniform. TOS Red Ops uniform v1, TNG Red Command Uniform v1, TNG Yellow Ops Uniform v1+2, TNG/DS9 Yellow Ops Dress Uniform, DS9 Yellow Ops Uniform v1+2.

Problematic Rank History

The character of Miles O'Brien, and the exact rank he held in Star Trek, has a history of its own spanning the length of the character's existence. In thirteen years of the character's appearances, only in the last four was his rank established to be presumably Senior Chief Petty Officer (although this term was never directly used onscreen). Through various other stages of the character's development, O'Brien was referred to as a Crewman, a Lieutenant, and various script notes indicated he was a "Warrant Officer." The novelization of DS9: "Emissary" indicated O'Brien held a rank known as "Ensign Junior Grade".

The exact history of O'Brien's ranks are as follows:

1987: Appears in TNG: "Encounter at Farpoint" and is referred to as “Conn”. In this episode, O'Brien wears the single pip of a Starfleet Ensign (1). In TNG: "Lonely Among Us" appears again, with the same insignia, credited as First Security Guard.

1988: Appears in TNG: "The Child", credited as Transporter Chief. Wears the two pips of a Starfleet Lieutenant (2). In TNG: "Where Silence Has Lease" he appears wearing the same uniform and insignia as "The Child" and is directly addressed by Commander Riker as "Lieutenant", seemingly indicating that O'Brien is an officer.

1989: O'Brien's surname is mentioned for the first time in TNG: "Unnatural Selection".

1990: Appears in TNG: "Family" and is addressed as "another Chief Petty Officer" by Sergey Rozhenko, even though he is shown wearing Lieutenant's pips, and is given a first (and middle) name, three years after his first appearance. From this point on, O'Brien's character is developed as a senior enlisted member of the Enterprise crew, although he would continue to wear the lieutenant's insignia.

  • Ronald D. Moore commented, "O'Brien was originally just a day player on TNG and very little, if any, thought went into his rank or background for quite a while. He officially became a Chief Petty Officer in "Family" when I wanted he and Worf's adoptive father to both be non-coms in contrast to Worf. Making him an enlisted man seemed to give us another color in the show and to open up another window into Starfleet that we hadn't explored before." (AOL chat, 1998)

1991: Appears in TNG: "Data's Day" wearing his usual uniform and insignia. At the end of the episode, O'Brien wears a dress uniform also with the two pip insignia of a Lieutenant.

1992: Appears in TNG: "Realm of Fear" where O'Brien is given direct orders by Reginald Barclay (who is a Lieutenant Junior Grade) thus firming up the idea that O'Brien is an enlisted NCO as opposed to an officer. This episode marks the first time that O'Brien wears the single hollow pip with his regular uniform (3). (The Star Trek Encyclopedia defines this as the insignia of a "Chief Warrant Officer" although the term is never used onscreen.)

1993: Appears in DS9: "Emissary" as "Chief of Operations". For the next three years, O'Brien wears a single hollow pip insignia with his rank again very much in question. Script notes from several Deep Space Nine episodes indicate he is a "Warrant Officer" while the pilot's novel version states O'Brien is an "Ensign Junior Grade" (3).

1994: Appears in DS9: "Shadowplay" where his title is stated to be Senior chief specialist. Appears also in the past segment of TNG: "All Good Things..." wearing the the single pip of a Starfleet Ensign which is consistent with what was worn during "Encounter at Farpoint" (1). However, the Star Trek: The Next Generation Companion incorrectly reports that O'Brien wears a single hollow pip during the episode.

  • In DS9: "Facets", after Nog passes the entry exam for Starfleet Academy, Miles mentions to Bashir that if Nog graduates from the Academy, he [Miles] will have to address Nog as "sir." Despite this, Nog would (upon becoming an Ensign) still refer to the Chief as "sir."

1995: By the time of DS9: "Hippocratic Oath", O'Brien has begun to wear a new insignia reminiscent of the chevron rank used by modern day Master Chief Petty Officers in the U.S. Navy (4). In this episode, a Jem'Hadar familiar with Starfleet insignia, identifies it as a Chief Petty Officer insignia. Presumably it was actually Senior Chief Petty Officer, as the word Senior was used in "Shadowplay", so the Jem'Hadar presumably simply left out the distinction.

Corresponding rank pins
Tng ensign Tng lt Tng chief Ds9 scpo
1 2 3 4

Possible explanations for O'Brien's various titles and insignia include:

  • During some points of The Next Generation, O'Brien may have held a field commission as an officer, which would explain why Riker once called him a Lieutenant. His continuous wearing of two pips (which is the standard insignia of a Lieutenant) might be a type of "honorary insignia" even though he was later clearly referred to as a Chief Petty Officer.
  • Starfleet non-commissioned officer insignia might be identical to officer insignia, with the number of pips worn by an NCO indicating level of seniority as a Chief Petty Officer. Under this system, one pip would equal a Chief Petty Officer, two a Senior Chief, and three a Master Chief. With O'Brien wearing two pips throughout The Next Generation, this would equate with his final rank of Senior Chief Petty Officer in Deep Space Nine.

Some problems with assuming that O'Brien is a Starfleet Chief Petty Officer include:

  • The entire backstory seen in TNG: "The Wounded" reveals that O'Brien was once a senior department head officer under the command of Captain Benjamin Maxwell. With O'Brien being a Chief Petty Officer onboard the Enterprise, it stands to reason that he was either a very junior CPO or perhaps even an ordinary Petty Officer under Maxwell. With the duties O'Brien was stated to have held (Tactical Officer), this creates a problem since nowhere else in Star Trek has an enlisted person been seen holding such a high level position.
  • At one point, O'Brien appears to have officers working for him. Such was the case in TNG: "Clues" where O'Brien states that an Ensign was "one of his technicians". This may be explained by O'Brien holding a type of "positional authority" which would grant him authority to officers due to his position as Transporter Chief, even though he was militarily junior. This would continue well into his tenure on Deep Space Nine, with an ensign in DS9: "Emissary" addressing him as "sir", several members of his staff appearing to be ensigns or lieutenants and Nog clearly being subordinate to O'Brien despite holding the rank of ensign.
  • Julian Bashir once remarked that O'Brien had attended Starfleet Academy (DS9: "Trials and Tribble-ations"), which is a training school for commissioned officers and not NCOs. Ronald D. Moore remarked, "This is a mistake, plain and simple. If you want to rationalize it, I suppose we could say that the enlisted training program also takes place at the Academy." (AOL chat, 1998) The idea of Starfleet Academy training enlisted personnel was also backed up by statements of Simon Tarses in TNG: "The Drumhead".

External links

Community content is available under CC-BY-NC unless otherwise noted.

Fandom may earn an affiliate commission on sales made from links on this page.

Stream the best stories.

Fandom may earn an affiliate commission on sales made from links on this page.

Get Disney+