A sentry ship was a type of space craft used by a species in the Delta Quadrant which the Borg knew as Species 116. These vessels were posted at specific locations to prevent the passage of the Borg into the territory of Species 116.

In 2374, Arturis, a member of Species 116, told Captain Kathryn Janeway and Seven of Nine that the sentry ships belonging to his people had provided little defense when the Borg finally managed to invade his homeworld. (VOY: "Hope and Fear")