The Galaxy-class starship is a Federation deep-space exploratory starship, one of Starfleet's most powerful and advanced vessels. It was designed to execute deep-space exploration missions including charting and mapping, first cultural contact scenarios, and full biologic and ecologic studies. The starship's saucer section can be separated from the drive section during emergencies. The Main Bridge is on Deck 1 of the Saucer, while the Battle Bridge is on Deck 8 in the Engineering Hull.

The U.S.S. Enterprise NCC-1701-D was designed and built at Utopia Planitia Fleet Yards orbiting Mars and was launched and officially commissioned in October 2363. The U.S.S. Enterprise-D was the third Galaxy-class starship built. The first was the U.S.S. Galaxy NX-70637 prototype commissioned in 2357, and the second was the U.S.S. Yamato NCC-71801 commissioned in 2362. The U.S.S. Odyssey NCC-71832 and the U.S.S. Venture NCC-71854 soon followed. Commander Orfil Quinteros was supervisor of the Galaxy-class Starship Development Project. Dr. Leah Brahms was one of the chief designers of the warp propulsion system.

The Galaxy-class Starship Development Project was approved in 2343. Pursuant to Starfleet Exploration Directive 902.3, the following objectives were established for the Galaxy Class Starship Development Project: (1) To provide a mobile platform for a wide range of ongoing scientific and cultural research projects; (2) Replace aging Ambassador- and Oberth-class starships as primary instruments of Starfleet's exploration programs; (3) Provide autonomous capability for full execution of Federation policy in outlying areas; (4) Incorporate recent advancements in warp powerplant technology and improved science instrumentation.

In 2372, the Enterprise-D was destroyed at Veridian III. A Klingon warbird, commanded by the renegade Klingons Lursa and B'Etor of the Duras family, found the Enterprise's shield modulation and hit the ship with modulated photon torpedoes. The Enterprise destroyed the Klingon ship, but the damage was not repairable. The crew was evacuated to the saucer section and the ship separated. The damage caused the warp core to breach and the resulting explosion caused the saucer section to crash on Veridian III. The ship was not salvagable and the new Sovereign-class starship U.S.S. Enterprise registry NCC-1701-E was launched in 2372.

By 2374, there were a total of 12 Galaxy-class starships in active commission, which played a major part in the Federation task force against the Dominion.

After the U.S.S. Enterprise NCC-1701-D crashed on Veridian III, the remains of the saucer section were retrieved and sent to the Fleet Museum at Athan Prime. Former chief engineer Geordi La Forge spent over two decades restoring the ship to its former glory, using the star drive section from the U.S.S. Syracuse NCC-17744.