Sentinel could refer to:
- Marcus Langston, Code name Sentinel; a comic book superhero and member of Youngblood.
- Karima Shapandar, Code name Omega Sentinel; Comic book superhero and member of Excalibur.
- Alan Scott, Also known as the original Green Lantern; Went by the name of Sentinel during the early-mid 1990s.
- Jacob Roseman, Israeli action hero; member of U.N. Force.
- Sentinels, A series of robots used for hunting down mutants.
- Omega Sentinel, Karima Shapandar; Sentinel cyborg.
- Sentinel MK I, The first model of Sentinel; created by Bolivar Trask
- Sentinel MK II, The second model of Sentinel; created by Larry Trask
- Sentinel MK III, The third model of Sentinel; created by Stephen Lang
- Sentinel 3.14159, A mutated MK III Sentinel and foe of Wolverine and Jubilee
- Sentinel Unit 2, Master Mold of the Ant Hill Sentinels; Fought the Avengers.
- Sentinel Unit 23, An MK III Sentinel in service at the Ant Hill; Revived by Sentinel 3.14159.
- Sentinel Unit 66, An MK III Sentinel in service at the Ant Hill; Revived by Sentinel 3.14159.
- Sentinel Unit 86, An MK III Sentinel in service at the Ant Hill; Revived by Sentinel 3.14159
- Sentinel Unit 99, An MK III Sentinel in service at the Ant Hill; Revived by Sentinel 3.14159.
- Sentinel A-7, A MK III Sentinel and foe of the Falcon.
- Tri-Sentinel, A mutated combination of 3 MK III Sentinels; foe of Cyclops.
- Wild Sentinels, An upgraded model of Sentinel; Deployed to destroy Genosha.
- Sentinel Squad O.N.E., A team of manned Sentinels.
- Sentinel orb, Killer spheres from the Phantasm film series.
- Sentinel Services, A government mutant watchdog agency featured on The Gifted.
- Sentinels of Magic, A team of super-powered magic users featured in DC Comics titles.