Leonard H. McCoy, MD was a noted physician and scientist of the 23rd and 24th centuries. McCoy was an accomplished surgeon, physician, psychologist, and exobiologist, and was also considered an expert in space psychology. As ship's surgeon and chief medical officer, he served aboard the USS Enterprise and USS Enterprise-A for a combined twenty-seven years.
Dr. Leonard McCoy was born in the "Old South" region of North America on Earth, in 2227, according to Starfleet records. He was the son of David McCoy. (Star Trek III: The Search for Spock; TAS: "Once Upon a Planet"; TNG: "Encounter at Farpoint")
McCoy was attending the University of Mississippi during the mid-2240s when he met the joined Trill Emony Dax, who was visiting Earth to judge a gymnastics competition. While Jadzia did not go into detail regarding the exact nature of their relationship, much may be inferred from her statement that "he had the hands of a surgeon". (DS9: "Trials and Tribble-ations")
He began studying medicine in or before 2245. While in medical school, McCoy and his friends used to play practical jokes on each other all the time. For example, they would substitute real drinking glasses with trick drinking glasses, causing the target drinker to spill on their shirt. (TAS: "The Practical Joker", "The Pirates of Orion")
In 2251, McCoy led a massive inoculation program on planet Dramia II, where he saved a Dramian colonist, named Kol-Tai, from a strain of the Saurian virus. Shortly after McCoy departed, Dramia II was struck by a plague which killed nearly all of the colonists. (TAS: "Albatross")
By 2253, McCoy had developed a surgical procedure for the humanoid brain; grafting neural tissue to the cerebral cortex, followed by the creation of an axonal pathway between the tissue graft and the basal ganglia. (VOY: "Lifesigns")
After promotion to lieutenant commander, McCoy was stationed at Capella IV where Capellan lack of interest in medical aid or hospitals ensured a short visit, lasting only a few months, before eventually joining the USS Enterprise's five-year mission in 2266. The knowledge of Capellan customs he acquired on this mission would prove valuable. (TOS: "Friday's Child"; Star Trek VI: The Undiscovered Country)
The five-year mission
Joining the crew of the USS Enterprise, already underway in 2266, McCoy replaced Dr. Mark Piper as the starship's chief medical officer and ship's surgeon. His assigned quarters were "3F 127" on Deck 9, section 2.
Kirk liberally used the nickname "Bones" for his doctor from this point on. (TOS: "The Man Trap") During a 2267 away mission on Pyris VII, Kirk made a special point to avoid calling McCoy "Bones", instead using the nickname "Doc", after finding themselves in shackles hanging alongside a skeleton. (TOS: "Catspaw")
On stardate 1513.1, while conducting a routine medical examination of outpost personnel at the archaeological dig on planet M-113, McCoy became reacquainted with an old flame, Nancy Crater. Unbeknownst to McCoy, Nancy had been murdered and replaced years before by what became known as the "M-113 creature".
The last survivor of M-113's long-dead civilization was a telepathic shapeshifter who digested the salt content from its prey. Drawing from a potential food source's mental imagery, it appeared as sympathetic or attractive, and further hypnotized its victim before feeding; hence McCoy saw a vision of Nancy exactly as he had known her years earlier.
When the creature began taking the lives of Enterprise crew members on the surface and aboard the ship itself, McCoy's judgment was tainted by his past feelings for Nancy. It was only when Spock was assaulted and Captain Kirk's life was in jeopardy that Dr. McCoy was able to see past the illusion of Nancy, forcing him to fire a phaser on a sentient being, the last of its kind. (TOS: "The Man Trap")
Further investigation revealed that the thoughts in their minds were being recorded and brought to life by a vast underground factory. While walking through the glade with Yeoman Tonia Barrows, they discovered the dress of a princess, conceived from the thoughts of Barrows.
McCoy encouraged Barrows to try on the dress, and afterward begin to romance the yeoman, later stating that she should not be afraid "with a brave knight to protect her". Moments later a Black Knight appeared on horseback, bearing a lance.
Convinced it was illusion and could not harm him, McCoy stood his ground against a charge – impaled in the chest, he died instantly. McCoy was brought underground, healed, and returned to the surface with two cabaret chorus girls he once met on Rigel II. Barrow's obvious jealousy prompted McCoy to extricate himself from his fantasy girls, taking the Yeoman's arm instead. (TOS: "Shore Leave")
On stardate 3417, McCoy's tonsils, which had been removed some years earlier, re-grew when he was briefly under the influence of the Omicron spores. Although he took part in the subsequent mutiny, he returned with the rest of the crew after the spore's influence was eradicated. (TOS: "This Side of Paradise")
During an investigation of temporal disturbances over an ancient planet, McCoy accidentally injected himself with an overdose of cordrazine, resulting in psychosis and paranoid delusions and he escaped to the planet's surface. Kirk, Spock, and a landing party followed him into the ruins of an ancient civilization, where they discovered the Guardian of Forever, an ancient time portal device.
Still psychotic, McCoy entered the device, transporting himself into Earth's past, creating a history without a Federation or Enterprise. Kirk and Spock followed him back to 1930 New York, where they meet social worker Edith Keeler.
After determining her death, averted by a recovered McCoy, is the focal point of the altered timeline, Kirk was forced to hold his friend back, allowing Keeler to die. (TOS: "The City on the Edge of Forever")
After the first discovery of a silicon-based lifeform on Janus VI, the Horta matriarch, McCoy is the first xenophysician to actually treat one of the creatures, healing the wounded mother with a bandage of thermal concrete. "By golly, Jim, I'm beginning to think I can cure a rainy day!" (TOS: "The Devil in the Dark")
He was also the first to describe the deadly habits and help find the cure for the flying neural parasites, a plague of one-celled flying creatures linked in a collective mind that had been sweeping across whole solar systems and destroying all humanoid life. (TOS: "Operation -- Annihilate!")
After the death of the Teer, the Enterprise landing party fled with the Teer's pregnant wife, Eleen. McCoy's truculent patient required an atypical bedside manner (i.e. "a right cross"), but he delivered the newborn High Teer, the rightful leader of the Capellan tribes.
Eleen, having grown fond of McCoy, named the child Leonard James Akaar, much to Spock's annoyance, who commented that the name would cause Kirk and McCoy to become insufferably pleased with themselves for at least a month. (TOS: "Friday's Child")
Although possessing limited surgical experience in Vulcan anatomy and physiology, McCoy successfully operated on Ambassador Sarek of Vulcan, Spock's father, when Sarek suffered from a faulty heart valve and subsequently near-fatal heart attacks. With blood donations from Spock, McCoy performed open heart surgery on Sarek while the Enterprise shuddered under the attack of hostile Orions.
Despite the distractions of his captain being knifed in the back, phaser attacks on the ship, and his blood donor attempting to get up and report to duty during the procedure, McCoy successfully completed the operation and Sarek fully recovered. (TOS: "Journey to Babel")
While mapping near the Sigma Draconis star system, the USS Enterprise encountered an Eymorg starship, whose occupant, Kara rendered the crew unconscious. Upon waking, they discovered that Spock's brain had been stolen.
It fell on McCoy to find a way to keep Spock's body alive; McCoy not only managed this, but also fitted him with a control system to move Spock's body remotely. When Spock's brain was located on Sigma Draconis VI, wired to the planet's environmental control system to care for its inhabitants, it fell on McCoy to use an advanced Great Teacher machine to learn how to replace the brain back within his body.
The effects of the teaching machine quickly wore off, but not before McCoy had reconnected Spock's autonomic and speech centers, enough for the Vulcan to verbally assist the doctor with the rest of the procedure and reconnect the rest of his voluntary functions. (TOS: "Spock's Brain")
In 2267, the USS Enterprise found the USS Defiant floating in and out of interphase space, its crew having apparently killed each other from space madness. When the Enterprise crew soon exhibited the same symptoms, McCoy discovered that prolonged exposure to the effects of interphase were causing the episodes. The symptoms were alleviated after McCoy created and administered a radical derivative of theragen (a Klingon nerve gas) mixed with drinking alcohol. (TOS: "The Tholian Web")
In 2268, McCoy was diagnosed with a terminal disease known as xenopolycythemia; he was given one year to live. Shortly thereafter, the Enterprise encountered the Fabrini asteroid-ship Yonada where he met their high priestess, Natira.
McCoy joined Natira and the Fabrini by having an instrument of obedience subdermally implanted into his body. He would later change his mind about staying with the Fabrini, choosing rather to search the galaxy to discover a cure for his disease.
Kirk and Spock discovered that the Fabrini, in fact, had the cure for xenopolycythemia in their databanks, curing McCoy and allowing him to continue his life aboard the Enterprise. (TOS: "For the World is Hollow and I Have Touched the Sky")
Around stardate 5371.3, Captain Kirk consulted McCoy to get his expert psychological opinion on whether the inhabitants of the planet Mantilles should be warned of the impending danger of an unidentified cosmic cloud that was approaching, and preparing to consume the planet.
McCoy figured that with only four hours and ten minutes until the cloud reached the planet, he was certain that there would be planet-wide panic, which Kirk clarified as "blind panic." Spock, however, recommended otherwise, and noted that if they told the inhabitants of the situation, they may be able to save a small fraction of the population. McCoy then agreed with Spock, after learning that Bob Wesley was governor of the planet, and urged Kirk to contact the governor. (TAS: "One of Our Planets Is Missing")
Later that year, McCoy was among the landing party that beamed down to inspect the planet Taurus II. He was among those affected by the glandular secretion of the Taurean females, known for controlling the male mind.
This caused McCoy to be drained of his "life force", making him age at a rate of ten years per day. Unable to counteract the effects of rapid aging, McCoy employed a hypospray of cortropine on himself and the landing party to help alleviate their conditions. He and the landing party were eventually recovered by an all female Enterprise security detachment lead by Uhura and returned to their previous ages by use of their molecular pattern stored in the transporter system. (TAS: "The Lorelei Signal")
In 2270, following a delivery of medical supplies to Dramia, McCoy was arrested for the wanton mass murder of the colonists of Dramia II from some nineteen years earlier. McCoy feared that he might have accidentally been responsible for the plague that killed the Dramians and that he might be found guilty.
Meanwhile, the Enterprise visited Dramia II and discovered a survivor, named Kol-Tai, who wished to help acquit McCoy of the charges. On the journey back to Dramia they passed through an aurora, which was later discovered to be the source of the plague.
Spock helped McCoy break out of the Dramian prison in order for the doctor to help find the cure for the plague that was now unleashed aboard the Enterprise. McCoy discovered the cure in Saurian virus antibodies and was able to save the crew. McCoy was later honored by the Dramians in a series of ceremonies, for his significant achievements in the field of interstellar medicine. (TAS: "Albatross")
On stardate 5499.9, while exploring the ocean planet Argo to study the regular seismic disturbances there, Kirk and Spock were separated from the rest of the landing party during an attack from an aquatic predator.
They were found later, but adapted for water-breathing, even possessing gills and webbed hands. Dr. McCoy was able to stabilize their condition aboard the Enterprise, but could not find a reversal for their condition. He endorsed their going back to Argo to investigate the mystery.
Kirk and Spock were able to locate the underwater city of the Aquans, and discovered a medical treatment within the city's records which could reverse their condition (utilizing the venom of another dangerous predator, the sur-snake). After obtaining a sample of venom, McCoy was able to synthesize a vaccine.
On stardate 5591.2, McCoy returned with the others to the Shore Leave Planet for shore leave once again. They soon discovered, however, that the Caretaker had died and the planet's central computer was rebelling against its programming, assaulting the landing party with dangerous manifestations.
McCoy was able to trick the planet into taking Spock beneath the surface by injecting him with melanex, an anesthetic which induced unconsciousness and odd skin discoloration in the Vulcan. McCoy and Sulu were later in danger of being incinerated by another of the planet's manifestations, a fire-breathing dragon, but were rescued when Uhura and the others were able to "talk down" the planet's computer. (TAS: "Once Upon a Planet")
As an "old country doctor" in the 23rd century
McCoy frequently displayed a very love/hate attitude towards technology. Although he was a great believer in the body's own natural ability to heal and felt that a little suffering was good for the soul, he also held 23rd century medicine in high esteem and frequently lamented how barbarous medicine used to be in the past - when on Earth in 1986, he angrily dismissed the medical technology of San Francisco's Mercy Hospital, state-of-the-art for the time, as "medieval" compared to what he knew. (TOS: "The Corbomite Maneuver", "The City on the Edge of Forever"; Star Trek IV: The Voyage Home)
While technically only lieutenant commander in rank, McCoy was still the only person on the Enterprise who could talk back to the Captain and get away with it. Although not without apology when wrong, he displayed a unique individuality and plain-spoken character which certainly clashed with the service, considering himself a doctor first and an officer second. This pugnacious attitude surfaced on a number of missions. Despite his sardonic wit, and curmudgeonly personality, McCoy is very compassionate, and cares deeply about all living things.
While on Miri's planet, McCoy discovered a vaccine for the deadly life prolongation complex virus which had killed all the adults on the planet and left the children with impossibly long life spans. Although completely unsure of the dose, McCoy "shot from the hip," as it were, injecting himself with the vaccine and successfully providing the landing party with a cure. (TOS: "Miri")
Upon the conclusion of the historic five-year mission in 2270, then-Commander McCoy, always modestly proclaiming himself to be "just a good ol' country doctor," retired his commission and proceeded to grow a beard. (Star Trek: The Motion Picture)
On stardate 7210, two and a half years later, McCoy's commission was reactivated by Fleet Admiral Nogura, using a "little-known, seldom-used, reserve activation clause" at the request of now Admiral James T. Kirk. McCoy served as chief medical officer during the V'Ger encounter, and afterward continued to serve with his shipmates in this capacity aboard the newly refitted Enterprise. (Star Trek: The Motion Picture)
Years later, on stardate 8130.3, Dr. McCoy served as a Starfleet Academy instructor aboard the Enterprise under Captain Spock, helping to acclimate new Starfleet doctors and nurses to shipboard medicine, and evaluating cadets during intense psychological tests such as the Kobayashi Maru scenario. However, during what was supposed to be a three-week training cruise, the Enterprise was attacked by Khan Noonien Singh, who sought revenge for his imposed exile by Kirk and the subsequent death of his wife. McCoy accompanied Kirk in the landing party to rescue the surviving scientists of Project Genesis, and was able to witness the results of Carol Marcus' work on the project beneath the Regula planetoid.
Back aboard Enterprise, he continued to treat casualties during the Battle of the Mutara Nebula. He was present in main engineering when Captain Spock arrived with the intention of entering the highly radioactive dilithium chamber to reactivate the ship's warp drive, so that Enterprise could escape Khan's suicidal ploy to kill them all with the Genesis Device. McCoy objected, but Spock felled him with a Vulcan nerve pinch and (almost as an afterthought) deposited his katra within McCoy's mind. Following their escape and Spock's death, McCoy grieved with Kirk and the rest of the crew as Spock was laid to rest on the newly formed Genesis Planet. (Star Trek II: The Wrath of Khan)
On their return to Earth, as the rest of the crew found that Enterprise was to be decommissioned, McCoy began to suffer increasingly erratic behavior, making odd requests of Kirk to return to Vulcan, and even sounding like Spock at times. Although at first it was thought he was only under too much stress, McCoy soon found himself placed under protective custody after making several inquiries into securing transportation to the newly restricted Genesis Planet. The significance of the Vulcan katra was explained to Kirk by Spock's father Sarek, and with their careers at stake, Kirk and his crew took it upon themselves to rescue McCoy, steal the Enterprise and take both to Genesis to recover Spock's body for return to Vulcan.
Although Enterprise was disabled and Kirk's son killed by rogue Klingons, the crew managed to commandeer the attacking Klingon vessel and take McCoy and the rejuvenated Spock on to Vulcan. Spock's katra was restored via the fal-tor-pan, an ancient, legendary Vulcan technique (Star Trek III: The Search for Spock). Although it was not generally known whether another species could serve as a "keeper of the Vulcan katra", McCoy appeared to suffer no lasting ill effects from the incident.
While returning to Earth with his shipmates to stand trial for the many violations in Starfleet regulations committed in saving Spock, McCoy discovered with the others that an unknown probe was intent on sterilizing the planet after replies to its broadcasts went unanswered. Spock deduced that the intended recipients of the probe's transmissions were extinct Humpback whales, and McCoy soon found himself a somewhat reluctant participant in Kirk's plan to time travel back to 20th century San Francisco to recover a pair of whales and save their future. McCoy was included in Sulu's and Captain Scott's team to recover supplies for the construction of a whale tank aboard their ship.
He later led a rescue team into a San Francisco hospital to save the critically-injured Chekov, pausing just enough to also provide an elderly lady suffering from kidney failure with some 23rd century medicine, and berate several 20th century physicians on their methods of practice. Accompanying his shipmates and the whales back through time to successfully save Earth from the Whale Probe, McCoy was acquitted with the rest of the crew for their offenses, and returned to duty aboard the newly commissioned USS Enterprise-A. (Star Trek IV: The Voyage Home)
Afterward, while enjoying a well-deserved leave with his close friends Kirk and Spock, McCoy also berated both the others (Kirk for taking unnecessary risks, Spock for apparently not completely becoming his old self after the re-fusion with his katra). Underneath, McCoy's real lament was for lacking a true family, and always being "stuck", as it were, with the crew of the Enterprise. During the rescue mission that immediately followed to save the ambassadors of Nimbus III, the Enterprise was hijacked by the renegade Vulcan Sybok, who forced McCoy to reveal his secret pain, the loss of his father, to Kirk and Spock (see "Family and relationships" below). In the events that followed and their return to Earth, McCoy finally came to terms with his loss and accepted the love and camaraderie of his two friends, who remain his enduring family, as they began singing songs around a campfire. (Star Trek V: The Final Frontier)
Shortly after stardate 9522, in 2293, the Enterprise was sent on a diplomatic mission to escort a Klingon envoy to Federation space for peace talks. When the Enterprise mysteriously appeared to fire on the ship of Klingon Chancellor Gorkon, Dr. McCoy beamed aboard with Captain Kirk to assist with casualties. McCoy attempted to save the life of Gorkon, who was critically wounded by an assassin's phaser, but was hindered by his limited knowledge of Klingon anatomy and physiology. The chancellor died, and McCoy was arrested with Kirk and charged with his assassination.
Kirk and McCoy were put through a show trial by the Klingon Empire, and although McCoy was able to draw a laugh from the assembled Klingons with an off-the-cuff quip, neither had much of a chance of defending their case. Handed a life sentence of hard labor they were then taken to the penal asteroid Rura Penthe to live it out. Luckily, McCoy and Kirk were rescued by Spock in time to discover the roots of the Khitomer conspiracy and disrupt a second assassination attempt at the peace talks at Khitomer. It was McCoy who assisted Spock in modifying a photon torpedo with a plasma sensor, so that it would home in on Klingon General Chang's attacking cloaked ship. McCoy then helped prevent the assassination of the Federation president, safeguarding a conference that fostered in an eighty-year era of peace between the Federation and the Klingon Empire. (Star Trek VI: The Undiscovered Country)
On stardate 41153.7, the 137-year old Admiral Leonard McCoy inspected the USS Enterprise-D during its first mission. He commented on the great significance of the ship's name to Lieutenant Commander Data, telling Data "You treat her like a lady... and she'll always bring you home." (TNG: "Encounter at Farpoint")
Family and relationships
An early ancestor of McCoy's, his great-great-grandfather, was a noted gardener, having had one of the finest gardens in the South. He also was noted for his own excellent weedkiller. (TAS: "The Infinite Vulcan")
McCoy suffered many family hardships early on in life, which eventually helped mold him into the prominent individual he eventually became. It began when McCoy was forced to face the harsh reality of his father's bout with a painfully incurable disease.
His father pleaded with McCoy to release him from the pain, but McCoy could not, as he was adamant in attempting to find a cure. Seeing his father suffer so painfully, however, moved McCoy to soon acquiesce and take his father off life support.
Soon after a cure was discovered, and McCoy subsequently lived many years in regret for causing his father's apparently needless death. (Star Trek V: The Final Frontier)
McCoy eventually married and had a daughter named Joanna. Sadly, McCoy's marriage ended in a bitter divorce, and he was separated from his daughter, deepening his hardships. His daughter eventually moved to the planet Cerberus to attend school, where she nearly died, in 2260, when the planet experienced a crop failure.
Fortunately, Cerberus was saved by kind actions of Carter Winston. McCoy was quite grateful for this deed and expressed the most sincere thanks to Winston, ten years later, when he was rescued by the Enterprise. (TAS: "The Survivor")
In 2254, McCoy became romantically involved with the future Nancy Crater. Nancy nicknamed her beloved boyfriend "Plum". They walked out of each others lives in 2256, and did not see each other again, although in 2266, McCoy met a creature who mimicked Nancy. (TOS: "The Man Trap")
In 2268 (during his stay on the Yonada), McCoy fell in love with and married Natira. Though technically the marriage could be considered annulled by the removal of his instrument of obedience, McCoy and Natira still felt strongly for each other and he asked her to come with him when he left. She declined, indicating that her place was with her people.
The two planned to be reunited just over a year later, when Yonada reached the solar system that was to be the new home for its people. (TOS: "For the World is Hollow and I Have Touched the Sky")
McCoy was not above kicking back with a good drink with the captain now and again, regularly keeping stashes of vintage saurian brandy and other libations with the controlled substances in sickbay. (TOS: "The Corbomite Maneuver", "The Enemy Within")
Displaying a fondness for the native alcoholic beverages of his region of Earth, such as Kentucky bourbon and Tennessee whiskey, his favorite drink was believed to be the mint julep. (TOS: "This Side of Paradise") He also made a Finagle's Folly "known from here to Orion." (TOS: "The Ultimate Computer") He was even known to put whiskey in baked beans. (Star Trek V: The Final Frontier)
His closest friends aboard the Enterprise included Captain Kirk and, begrudgingly, Spock. McCoy's friendship with Kirk dated back well before Kirk took command of the Enterprise, and he often served as a sounding board and voice of conscience for the young captain.
His legendary feud with the half-Vulcan science officer (borne more from dispute over the merits of emotion versus logic rather than true prejudice) camouflaged the genuine mutual respect and friendship the two had. Over time, the three appeared to form nearly a single personality, with McCoy ever emotional and passionate, Spock ever objective and logical, and Kirk intuitive; the focus, direction and driving force combining the best of the other two.
While he and Kirk were observing Spock's marriage rites on Vulcan, McCoy suddenly found himself watching his two best friends in a fight to the death over the entranced Spock's betrothed. In a covert, underhandedly sneaky Human move, he tipped the scales of the fight and saved Kirk's life by ostensibly injecting him with a tri-ox compound respiratory aid when he was actually injecting him with a neural paralyzer. When Kirk appeared dead, Spock snapped out of his trance and ended the marriage, only to gleefully find Kirk alive back on the Enterprise a short time later. (TOS: "Amok Time")
On Minara II, Kirk, Spock and McCoy were kidnapped by the Vians, and forced to choose between themselves which one would die in their experiments. Sacrificing himself for the others against their will, McCoy submitted to a level of torture which nearly killed him, only to be healed by the empathic Gem, another of the Vian's prisoners.
- "He/she's dead, Jim." (various episodes)
- "I signed aboard this ship to practice medicine, not to have my atoms scattered back and forth across space by this gadget." (TOS: "Space Seed")
- "Hey Jim-boy, y'all ever have a real cold, Georgia-style mint julep, huh?" (TOS: "This Side of Paradise")
- "Just a moment, Captain, Sir, I'll explain what happened. Your revered Admiral Nogura invoked a little-known, seldom-used reserve activation clause. In simpler language, captain, they drafted me!" (Star Trek: The Motion Picture)
- "Well Jim, I hear Chapel's an MD now. Well, I'm gonna need a top nurse, not a doctor who'll argue every little diagnosis with me. And they probably redesigned the whole sickbay too! I know engineers, they love to change things!" (Star Trek: The Motion Picture)
- "Jim, I'm your doctor and I'm your friend. Get back your command. Get it back before you turn into part of this collection. Before you really do grow old." (Star Trek II: The Wrath of Khan)
- "The bureaucratic mentality is the only constant in the universe. We'll get a freighter." (Star Trek IV: The Voyage Home)
- (Upon learning he was the recipient of Spock's katra via a mind-meld) "That green-blooded son-of-a-bitch. It's his revenge for all those arguments he lost." (Star Trek III: The Search for Spock)
- "Jim, you don't ask the Almighty for his ID!" (Star Trek V: The Final Frontier)
- Starfleet Legion of Honor
- Starfleet Surgeons Decoration
- Comparative Alien Physiology by Dr. McCoy is required reading at Starfleet Medical Academy through the 2370s.
- Capellan Teer Leonard James Akaar was named after McCoy (and his captain), after McCoy delivered him in 2267
- Admiral McCoy was invited to tour the USS Enterprise-D, during her maiden voyage in 2364.
- Holographic Doctors, under development in the 24th century, included McCoy in their templates.
- 2227: Born on Earth.
- 2240s: Attends the University of Mississippi; meets Emony Dax.
- 2250s: Commissioned to Starfleet
- 2260s: As a lieutenant commander, visits Capella IV briefly before joining the Enterprise.
- 2266-2270: Serves as ship's surgeon and chief medical officer aboard the USS Enterprise.
- 2270: Retires from Starfleet at conclusion of Kirk's five year mission.
- 2272: His commission is re-activated at Kirk's insistence, during V'Ger incursion.
- 2285: Instructor aboard USS Enterprise.
- 2286: Chief medical officer of the USS Enterprise-A.
- 2293: Imprisoned on Rura Penthe and subsequent escape helps to uncover the Khitomer conspiracy.
- 2364: Tours newly-commissioned USS Enterprise-D.
Leonard McCoy was played by actor DeForest Kelley. Several novelizations of movies have identified McCoy's full middle name as "Horatio", but this was never established on screen.
The Star Trek Concordance establishes that his daughter Joanna was born around 2249, and was in training to become a nurse. It also establishes that although they write each other often, Dr. McCoy's duties aboard the USS Enterprise keep the two apart. The Star Trek Chronology provides additional background information on his divorce and his daughter. This scenario establishes that as a result of the divorce McCoy leaves the private practice (which he apparently rejoins in 2270) to join Starfleet. "The Way to Eden" was originally written for and titled "Joanna", but was however rewritten and Joanna became Irina Galliulin The novel Shadows on the Sun has as one of its subplots the story of his marriage and divorce, when his ex-wife arrives on the Enterprise-A to help them deal with a crisis on a world that McCoy visited fresh out of medical school, only to die in the course of the mission – killed, ironically, by someone whose life McCoy saved on his first visit.
The Star Trek Encyclopedia speculates that Emony Dax and McCoy met around 2245, this based on the fact that McCoy appears to have not yet entered (or at least not yet completed) medical school when they knew each other. Jadzia Dax strongly implied that Bones and Emony were physically intimate, if only for a short time.
The animation for Star Trek: The Animated Series depicted McCoy as a full commander in both promotional artwork and in episode photography, although more than a few erroneous sequences of him with lieutenant commander insignia cropped up during the course of the series.
He was one of at least four Starfleet officers (along with Spock, Scott, and Sulu) under James T. Kirk to have attained the rank of captain, as he was a retired admiral during the events of "Encounter at Farpoint".
In David R. George III's novel, Provenance of Shadows, McCoy is portrayed as passing away peacefully in 2366, at home on Earth in present-day Georgia. In this story, he is married to Tonia Barrows, who is also still alive at advanced age during the story. Although they had been married for decades, when they married isn't exactly known.
In William Shatner's novels, McCoy is still alive and well in 2379 thanks to the use of artificial body parts, many of which he developed (he claims to be on his third heart, has a new set of lungs grown each month, and has around ten meters of cloned intestines inside him). He helps Julian Bashir remove a Borg implant from Kirk's brain, advising the young physician as to what to do due to his elderly condition, and is subsequently the first person Kirk sees upon regaining consciousness.
In the comic book adaptation of the Star Wars novel Dark Force Rising, McCoy (along with Kirk and Spock) makes a cameo on the planet Jomark.