In Star Trek: First Contact, Jean-Luc Picard commands the USS Enterprise-E.
The 1996 film is the eighth feature film in the Star Trek franchise and the second to star the cast of Star Trek: The Next Generation. Patrick Stewart plays Picard, who leads the Enterprise-E against the Borg during an attack on Earth’s past. The crew travels to 2063, the year humanity makes first contact with the Vulcans.
The ship is a Sovereign-class starship and replaced the USS Enterprise-D after that vessel was destroyed in Star Trek Generations. The Enterprise-E’s participation in the battle against the Borg is central to the film’s plot, while its time travel story connects the future crew with the historical moment that changes humanity’s place in the galaxy.
This question is sometimes confused with Star Trek: The Next Generation, where Picard commands the Enterprise-D. First Contact specifically features the newer Enterprise-E, making the ship designation an important identifying detail.