For other uses, see Leviathan.

Leviathan was an enormous machine entity or sentient starship which collected sentient lifeforms and placed them in a zoo in its interior. It was encountered by the USS Voyager in the Delta Quadrant. Among the races it collected were a group of Jem'Hadar who were not dependent on Ketracel White, and were presumably taken prior to the Jem'Hadar's enslavement by the Dominion. In addition a tribe of Vidiians that were abducted prior to the Vidiian Phage.

Leviathan attempted to collect Voyager, along with other Delta Quadrant species. After escaping, the Voyager crew discovered a record in Leviathan's computer banks of Willard Decker and Ilia merging with V'Ger, suggesting that Leviathan possessed a connection to V'Ger, possibly being descended from the same machine race. (VOY comic: "Leviathan")