By starship or station
- The Setlik III massacre. (DS9: "Tribunal")
- A soldier, Miles O'Brien kills a Cardassian during the massacre. (TNG: "The Wounded")
- He later operates a field transporter for the first time and saves thirteen men. (DS9: "Paradise")
- Several prisoners, including Raymond Boone, are taken by the Cardassians. (DS9: "Tribunal")
- O'Brien is declared the "Hero of Setlik III" after leading a group of two dozen men against a Cardassian regiment at the Barrica encampment. (DS9: "Empok Nor")
- O'Brien is transferred to the operations division and promoted to tactical officer. (TNG: "The Wounded")
- Under the command of Captain Blackwood, the Tombaugh is attacked and assimilated by the Borg. Amongst the crew is Ensign Stone, fresh out of the Academy. (VOY: "Infinite Regress")
- Warp engine control systems are installed on the USS Enterprise-D. (TNG: "Eye of the Beholder")
- Ensign Marla Finn begins a romantic relationship with Walter Pierce. She soon begins an affair with William Hodges and both are killed by a jealous Pierce in a plasma explosion. Afterward, Pierce vaporizes himself in the Enterprise's plasma stream. His Betazoid empathic trace is inadvertently left in the nacelle tube bulkhead. (TNG: "Eye of the Beholder")
- Stardate 40987.2: Starfleet reports Marla E. Finn and William Hodges as missing.
- Stardate 40999.4: The OSHC investigation into Finn's disappearance is terminated with no result.
- Stardate 40164.7: The Victory investigates the mysterious disappearance of 49 people on the Tarchannen III outpost. Ensign Geordi La Forge is involved in the away team. (TNG: "Identity Crisis")
- The last Klingon raid into Federation space occurs for at least the following seven years. (TNG: "Aquiel")
- Stardate 39355.5: Dekon Elig is killed by phaser fire on Velos VII. (DS9: "Babel")
- On Mordan IV, construction workers use steelplast for the sealing off of segments of tunnels under the principal city of the planet. An example of a tunnel segment sealed from adjoining tunnels is the subsidiary tunnel M-4. (TNG: "Too Short a Season")
- Patterson Supra is born. (TNG: "Disaster")
- Cadet Ro Laren graduates from Starfleet Academy. (TNG: "The Next Phase")
- Beverly Crusher is promoted to Commander after passing the bridge officer examination. (TNG: "Thine Own Self")
- Raymond Boone is killed. He is replaced by a Cardassian spy and returned to Starfleet. Within the year, "Boone" resigns from Starfleet, leaves his wife, and moves to a Cardassian border planet. (DS9: "Tribunal")
- Rugal, son of Kotan Pa'Dar, is kidnapped by a Cardassian officer and taken to the Tozhat Resettlement Center after his mother is killed in a Bajoran Resistance attack. He would be adopted by Bajoran Proka Migdal. (DS9: "Cardassians")
- Fallit Kot hijacks a shipment of Romulan ale. He is caught and sentenced to eight years in a labor camp. (DS9: "Melora")
- This is the last year in which Tom Paris feels he has a life that is worth risking. (VOY: "Threshold")
- Quark loans his cousin Gaila an amount of latinum to start up a munitions consortium. Gaila promises Quark to pay him back in a shuttle should he become a success. (DS9: "Little Green Men")
Alternate timeline events
- Upon graduating from Starfleet Academy, Natasha Yar is assigned to the first Galaxy-class battleship, the USS Enterprise-D.
Their are two sources for 40000s range stardates in this year:
- The log entry made by Ensign Anthony Brevelle in TNG: "Identity Crisis".
- The dates seen by Deanna Troi in a hallucination in TNG: "Eye of the Beholder". These dates were all in the 40000s range, even though they took place over several years.
There is some debate on the dating of the Setlik III massacre. O'Brien had previously stated his first use of transporter technology was in 2347 (TNG: "Realm of Fear"), and his Starfleet career began in 2350 (DS9: "Rules of Engagement"). The faux Boone specifically stated he left Starfleet in 2362 following the massacre. (DS9: "Tribunal").