She was among the medical personnel who were allowed entrance to Ten Forward to care for the wounded hostages taken by the Ux-Mal criminals possessing the bodies of Deanna Troi, Miles O'Brien, and Data. (TNG: "Power Play")
Off duty he had a drink at the bar in Ten Forward when Q met Guinan. (TNG: "Deja Q")
He passed Counselor Troi and Captain Picard in a corridor when the two were discussing the future of Lal, Data's daughter. Off duty, he visited Ten Forward later. (TNG: "The Offspring")
He manned an aft station on the bridge when Data detected unusual energy readings from the Captain's quarters. He also worked on the bridge when an impostor took the place for Captain Picard. (TNG: "Allegiance")
Together with a woman he attended the concert held for Ambassador Sarek in 2366. (TNG: "Sarek")
He shared a drink with a woman in Ten Forward when Commander Riker talked to Counselor Troi about the arrival of Lieutenant Commander Shelby. (TNG: "The Best of Both Worlds")
He was on duty in sickbay when the Enterprise-D brought the crew of the USS Brattain aboard and treated Andrus Hagan in sickbay. He talked to CrewmanMartinez. He remained in sickbay when Doctor Crusher treated several crewmembers because of their lack of dreams. (TNG: "Night Terrors")
He was part of the medical team which was allowed to enter Ten Forward to treat several wounded hostages while Deanna Troi, Miles O'Brien, and Data were possessed by Ux-Malterrorists (TNG: "Power Play") and was part of the medical team which treated the wounded crewmembers and colonists of the USS Denver in one of the cargo bays. (TNG: "Ethics")
He was working on an aft station of the bridge when the Enterprise-D arrived at Devidia II and was astonished when Captain Picard agreed to beam Data down to the surface (TNG: "Time's Arrow") and when the Enterprise-D answered the distress call of the transport ship Dorian. (TNG: "Man of the People")
He was working on an aft station on the bridge when the Enterprise-D discovered the Dyson sphere and the crashed USS Jenolan with Captain Montgomery Scott on board. (TNG: "Relics")
He was preparing cargo for Tagra IV in the shuttlebay when Geordi La Forge and Amanda Rogers loaded cargo into a shuttlepod. (TNG: "True Q")
He was on duty on the bridge and astonished when the "kid" Picard came onto the bridge and issued orders. Later he was among the crewmembers on the bridge when the Enterprise-D was taken over by renegade Ferengi. (TNG: "Rascals")
He was part of Doctor Crusher's theater group which encountered the changes in their text during a malfunction of the Enterprise-D caused by the connection with Data. (TNG: "A Fistful of Datas")
He was part of the medical emergency team which transported the Romulan officer Patahk from the transporter room to sickbay by using an anti-grav lift. He later assisted Dr. Crusher treating the Romulan in sickbay. (TNG: "The Enemy")
He passed Deanna Troi, Data, and Wesley Crusher in a corridor when the three were on their way to see Data's daughter Lal. Later he played a game of three-dimensional chess against a fellow officer in Ten Forward. (TNG: "The Offspring")
He worked on an aft station on the bridge when Commander Kurn held his speech and introduced himself as the new first officer. He also worked on his station when Data performed research regarding the attack on the Narendra IIIoutpost. (TNG: "Sins of the Father")
He passed the security team which went to the Captain's quarters after Data detected an unknown energy signal from inside the quarters. He later passed the quarters of Data when the Picard impostor interrupted the poker game and the sickbay. (TNG: "Allegiance")
Off duty, he passed Counselor Troi and Captain Picard in a corridor shortly after Lal was introduced to them. Later, wearing his blue uniform, he visited Ten Forward and had a drink when Lal was working as a waitress. (TNG: "The Offspring")
He passed Commander Riker and Captain Picard in a corridor when the two went to the transporter room to welcome Commander Kurn aboard (TNG: "Sins of the Father") and Captain Picard and Counselor Troi on their way to the transporter room to welcome Tam Elbrun aboard. (TNG: "Tin Man")
Off duty he attended the concert held for ambassador Sarek and his wife Perrin aboard the ship. (TNG: "Sarek")
He visited Ten Forward while Data, Geordi La Forge and Worf shared a drink and the Enterprise-D took a wounded Zalkonian aboard (TNG: "Transfigurations").
He was part of the crew which was forced to leave the main bridge and relocate in main engineering following a blue alert. He took the same turbolift as Captain Picard and was later working in main engineering on different consoles. (TNG: "Brothers")
He was walking in a corridor when a security team led by Worf passed him. He had to jump out of the way. Prior to this and also later he served on the bridge on an aft section console. (TNG: "Power Play")
He was part of the medical team which treated several wounded crewmembers and colonists from the USS Denver in the cargo bay after the Enterprise-D beamed them aboard. (TNG: "Ethics")
He was walking past Geordi La Forge and Captain Montgomery Scott in a corridor shirtly after Scotty was beamed aboard. (TNG: "Relics")
He was among the audience who listened Data's poetry reading in Ten Forward (TNG: "Schisms") and shared a drink with fellow crewmembers in Ten Forward while Amanda Rogers was aboard the Enterprise-D. (TNG: "True Q")
This lieutenant was played by regular background actor Mark Lentry who received no credit for his appearances.
This science officer was portrayed by background actress Cat Hayes who received no credit for her appearance.
This Starfleet doctor, holding the rank of a lieutenant, served aboard the Enterprise-D in 2365.
He was treating a patient's injured leg and reported to Doctor Katherine Pulaski that his knitter did not work. She advised him to use a splint and explained what a splint was and how he should use it. He had doubts about this method and called it crazy, but Pulaski refused his comment and ordered him to do it, saying it had been used for a long time - with his head, heart, and hands. (TNG: "Contagion")
She reported to Lieutenant j.g. Worf on thhe bridge and was interrupted when Lieutenant Commander Dexter Remmick started to accuse the senior staff. Later she was working on an aft station. (TNG: "Coming of Age")
She was also on duty on the bridge when the Enterprise-D took aboard Klingon fugitives. (TNG: "Heart of Glory")
She was seen aiding Riker after he was knocked out by the one of the borg who beamed aboard the ship for Picard. (TNG: "The Best of Both Worlds")
She passed Counselor Troi and Captain Picard in a corridor when the two were talking about Data's daughter Lal. Later, she was on duty in sickbay when Data asked for Crusher's advice. (TNG: "The Offspring")
She was again on duty in sickbay when Worf's brother Kurn was treated there after he was attacked by Klingon assassins on Qo'noS (TNG: "Sins of the Father") and when the Picard impostor astonished Doctor Crusher in her office. (TNG: "Allegiance")
She was part of the medical staff on duty in sickbay treating the Talarian cadets. She also tried to hold Jono. She later assisted Dr. Crusher treat Captain Picard (for injuries he suffered in an attack by Jono); she spoke the words "Yes, doctor" in response to Dr. Crusher's request for a medical instrument, then handed the instrument to the doctor. (TNG: "Suddenly Human")
She was one of the medical officers along with Gates, Martinez, and Jones who were briefed by Dr. Crusher in sickbay while searching for Wesley Crusher, Captain Picard and Dirgo. (TNG: "Final Mission")
She attended the wedding ceremony of Miles O'Brien and Keiko Ishikawa in Ten Forward. (TNG: "Data's Day")
Off duty, she had a drink with a male science officer in Ten Forward while Geordi La Forge talked to Guinan about his feelings for Dr. Leah Brahms. (TNG: "Galaxy's Child")
She assisted Dr. Crusher in sickbay treating all the minor injuries of the crew caused by their lack of REM sleep. (TNG: "Night Terrors")
She was off duty for a drink in Ten Forward shortly before the ship was hit by a cosmic string. (TNG: "Disaster")
She was on duty in sickbay when Captain Picard and Data were scanned for their Romulan prosthetics. (TNG: "Unification I")
She was talking to another crewmember in the corridor when Ves Alkar accomapnied Deanna Troi to her quarters after the mok'bara class. (TNG: "Man of the People")
She was on duty in sickbay when Dr. Crusher treated Commander Riker due to his insomnia. (TNG: "Schisms")
She was working in the shuttlebay when the crew prepared the cargo and technology for the planet Tagra IV. (TNG: "True Q")
She was working in sickbay when Dr. Crusher treated herself following exercise with Lieutenant Worf (TNG: "The Quality of Life") and when Dr. Crusher and Worf were treated in sickbay following their secret undercover mission. (TNG: "Chain of Command, Part II")
She was among the medical personnel in sickbay prepared for the attacked away team including the wounded Captain Picard. (TNG: "Tapestry")
In early 2370, she assisted Dr. Crusher bringing Deanna Troi into the mind of her mother Lwaxana with the help of the Cairn Maques. (TNG: "Dark Page")
She was talking to another crewmember in Ten Forward when Commander Riker and Admiral Erik Pressman visited the bar. (TNG: "The Pegasus")
This recurring Starfleet officer was played by a background actress with the last name Kai. She also worked as stand-in for Patti Yasutake but received no credit for her appearances.
Female medical technician
This female Starfleet officer worked as medical technician aboard the Enterprise-D in 2364.
She was one of the Starfleet officers who visited the shopping mall at Farpoint Station. Later she passed Commander Riker in front of the transporter room when he was beamed aboard the ship for the first time. (TNG: "Encounter at Farpoint")
She was on duty on the bridge when Captain Picard, Data and Doctor Crusher were trapped on the holodeck. (TNG: "The Big Goodbye")
This science division officer was among the personnel aboard the Enterprise-D evacuated from the stardrive section into the saucer section following the Q encounter. Later, when Dr. Crusher treated Geordi La Forge in sickbay, she was there on duty. (TNG: "Encounter at Farpoint")
She was among the medical personnel caring for the civilians in some quarters aboard the ship when only emergency power was available. She took some blankets from Deanna Troi. (TNG: "The Last Outpost")
Carrying some PADD's, she passed Captain Picard and the Edo Rivan in a corridor. (TNG: "Justice")
She was also roaming the corridors when Lwaxana Troi came aboard the ship (TNG: "Haven") and passed Jake Kurland in a corridor. (TNG: "Coming of Age")
She was working in main engineering when the Klingon Korris took over the control of the warp core. (TNG: "Heart of Glory")
She attended the concert in Ten Forward in late 2367 in which Data, Jenna D'Sora and Keiko O'Brien participated. (TNG: "In Theory")
She was again working on an aft station of the bridge when Gowron visited the Enterprise-D. Later, she was one of the officers standing in the row between the turbolift and the transporter room to honor Worf shortly before he left the ship. (TNG: "Redemption")
In 2368 she passed Lieutenant Worf in a corridor shortly before the Klingon talked to Counselor Troi about his son Alexander. (TNG: "New Ground")
She attended the memorial service held for Ro Laren and Geordi La Forge in Ten Forward. (TNG: "The Next Phase")
Off duty she was in Ten Forward when Commander Riker asked Guinan about her past on Earth. (TNG: "Time's Arrow, Part II")
She was also in Ten Forward when Reginald Barclay experienced physical problems due to his transporter accident (TNG: "Realm of Fear") and during Data's poetry reading. (TNG: "Schisms")
She was one of the crewmembers who prepared cargo in one of the shuttle bays for the planet Tagra IV. (TNG: "True Q")
This recurring science officer was played by background actress Brandy Pickett, who received no credit for her appearances.
In 2371, she was talking to fellow crewmembers in Ten Forward after Doctor Tolian Soran was beamed aboard the ship. Later, when Geordi La Forge was treated in sickbay following his return from the Duras sisters, she was on duty and carried a PADD. (Star Trek Generations)
This recurring sciences officer was played by background actress Gunnel Eriksson who received no credit for her appearances.
She brought Commander Riker a report into the observation lounge while the ship was docked at the McKinley Station. She received orders from Riker and passed Worf when leaving. Later she was in Ten Forward when Worf's parents paid a visit. (TNG: "Family")
In 2367 she participated in a mok'bara exercising with Worf, Geordi La Forge, Riker, Troi, and Gates. Later she worked on an aft station of the bridge when the Enterprise-D encountered the Paxans and lost a whole day. (TNG: "Clues")
This female science division officer accompanied to others into Ten Forward and sat down at a table near the bar. She stood up again when Chief O'Brien asked them to take a different table because he wanted to sit at this one. Due to the affection of Ambassador Sarek's uncontrolled emotions the officers started a fight and she fought against an operations division officer. (TNG: "Sarek")
This sciences division crewman experienced a hallucination of a raging inferno in an Enterprise-D corridor. Picard convinced him the fire wasn't real and ordered him to return to his post and await a ship-wide announcement. (TNG: "Where No One Has Gone Before")
This science division crewman was portrayed by stunt actor Dennis Madalone, who received no credit for this appearance, although his voice was heard in the episode ("How?" and "Yes sir"). It was his first Trek role and he went on to portray dozens of other characters as well as serving as stunt coordinator for The Next Generation (beginning with Season 3), Star Trek: Deep Space Nine, and Star Trek: Voyager.
It is possible this is either Ramos or Hedrick, as they were also played by Madalone.
Male science division officer
This science division officer served aboard the Enterprise-D in the late 2360s.
He was part of the away team which beamed down to the surface of Melona IV to scan the area after the attack of the Crystalline Entity. (TNG: "Silicon Avatar")
The same year he was among the medical personnel who cared for the wounded crewmembers in Ten Forward following the ships contact with a cosmic string. (TNG: "Disaster")
He passed Data and Wesley Crusher in a corridor shortly after Crusher beamed aboard the ship. (TNG: "The Game")
He was part of the medical team which went into Ten Forward to care for the hostages. (TNG: "Power Play")
He visited Ten Forward again while Deanna Troi talked to Guinan about Clara Sutter's behavior. (TNG: "Imaginary Friend")
He carried cargo and suitcases out of the shuttlebay following the repairs aboard a Romulan science ship. (TNG: "The Next Phase")
He passed the transporter room shortly after Samuel Clemens was beamed aboard. Later, he passed Clemens and Deanna Troi in a corridor and was working on an aft station of the bridge. (TNG: "Time's Arrow, Part II")
He was again working on the bridge when the crew investigated the malfunctions aboard the USS Yosemite. (TNG: "Realm of Fear")
He passed Commander Riker and Geordi La Forge in a corridor when the two discussed Riker's insomnia. (TNG: "Schisms")
He attended the ceremony held in Ten Forward in which Captain Picard transferred the command of the Enterprise-D to Captain Edward Jellico. (TNG: "Chain of Command, Part I")
This recurring science officer was played by background actor Gary Hunter, who received no credit for his appearances.
Male science division officer (alternate timeline)
This science division officer served aboard the Enterprise-D in an alternate timeline, created when the Enterprise-D went through time. In this timeline he had a drink in Ten Forward. (TNG: "Yesterday's Enterprise")
This science division officer was working in sickbay in 2367 and contacted Dr. Crusher over the com. He asked her to report to sickbay. Dr. Crusher then asked Commander Riker to accompany Vash. (TNG: "Qpid")
This science division officer was the father of Mason and lived with him aboard the Enterprise-D in 2364.
In this year, he and his wife were walking through a corridor with their son, when he disappeared. It was later revealed that he was kidnapped by the Aldeans who were not able to become children themselves. Mason's parents took part in a meeting in the observation lounge, led by Captain Picard and Dr. Crusher. (TNG: "When The Bough Breaks")
He was on duty on the bridge when the Enterprise-D visited Vagra II to rescue Counselor Troi. (TNG: "Skin of Evil")
She was among the Starfleet officers and civilians who were evacuated into the saucer section when the crew prepared to engage Q for a second time. Later she visited the Bandi shopping mall at Farpoint Station. (TNG: "Encounter at Farpoint")
She was walking in a corridor when a probe of the Edo God penetrated the hull and went through a corridor. She later passed Captain Picard and the EdoRivan in another corridor. (TNG: "Justice")
She left a room to prepare the rescue mission on Quadra Sigma III. Then she followed Dr. Crusher and listened to her instructions for the rescue mission while carrying medical equipment. (TNG: "Hide and Q")
When Lieutenant Commander Data gave the order for red alert and the evacuation of the Enterprise-D, she was among the people who ran through the corridors and left the ship by using the transporter to Starbase 74. (TNG: "11001001")
This medical technician was serving in 2371. He brought a mobile biobed to the transporter room following Commander La Forge's return by the Duras sisters. He rescued injured crewmembers from the bridge during the subsequent attack, and helped Dr. Crusher and Nurse Ogawa evacuate sickbay and find safe haven for ambulatory patients. He later evacuated injured crewmembers from the saucer section. (Star Trek Generations)
Although it is possible that this character may have been Ayala from Star Trek: Voyager, the stardate of Generations places it several months after USS Voyager was lost in the Delta Quadrant. Thus, it is entirely possible in this case, that he is an identical twin.
This medical technician was uncredited and played by regular extra Tarik Ergin.
This nurse assisted Doctor Katherine Pulaski during Counselor Deanna Troi's birth of Ian Troi in 2365. (TNG: "The Child")
This ensign was working as a nurse and was on duty in sickbay shortly after DoctorPaul Stubbs made his first experiments with "The Egg" aboard the Enterprise-D in the Kavis Alpha sector. She helped treat Dr. Stubbs after he was violently thrown around the bridge by ship malfunctions. She also watched the malfunctions of the food slot in sickbay. (TNG: "Evolution")
Her role was originally going to be a little larger but most of her scenes were cut. She would have treated Annette, who broke a leg during the episode and would have been hit by an energy burst emitted by the nanites when she wanted to get Annette and Eric two cups of hot chocolate from the malfunctioning replicator in sickbay. 
Nurse (early 2367)
This science division officer worked as nurse aboard the Enterprise-D in 2367.
She was present in sickbay when the crew treated the Talarian cadets and when Jono was overwhelmed by four members of the medical staff including Martinez. (TNG: "Suddenly Human")
She took care of the pregnant Juarez shortly before she gave birth in 2367. She called Dr. Crusher on the holodeck to inform her that Lieutenant Juarez's contractions were one minute apart, whereupon the doctor hurried to sickbay. After the Juarez baby was born, she tucked the boy in, shortly before Captain Picard came to the nursery to welcome the newest member of the ship. (TNG: "Data's Day")
Off duty she visited Ten Forward shortly before the ship was hit by a cosmic string (TNG: "Disaster") and when Commander Riker interrupted Counselor Troi's rendezvous with Chocolate ice cream. (TNG: "The Game")
This nurse was on duty in sickbay in early 2368 and treated a young boy when Berlinghoff Rasmussen visited sicjbay. Accompanied by a command division lieutenant, she later passed Rasmussen in a corrisor. (TNG: "A Matter of Time")
The science division crewman was played by Kenny Koch.
Science division crewmember (2364)
When the Enterprise-D stranded in a galaxy where dreams became reality this science division officer almost ran into Captain Picard, followed by a female command division officer. He told Captain Picard he needed his help and when Picard asked what was wrong he just asked him if he cannot see what is following him. He then left the corridor in a hurry. (TNG: "Where No One Has Gone Before")