- For other uses, see Neptune.
Neptune has at least thirteen moons, the largest of which is Triton. The second moon (by distance from Neptune) is Nereid which housed a Federation research facility in the 23rd century. (TOS - Section 31 novel: Cloak)
The RPG The Dominion War Sourcebook: The Fires of Armageddon, published by Last Unicorn Games after they had lost their Star Trek licence, states that prior to the Breen assault on Earth in late-2375, the Breen fleet attacked the outer defense perimeter of the Starfleet 3rd Fleet over Neptune.