Sentinel might refer to a person or thing that serves as a sentry, guard, or watch, or it might refer to:
- The Sentinel, a novel by Troy Denning featuring Kleef Kenric.
- The Sentinels, a novel by Geno and R.A. Salvatore featuring Maimun and the Stone of Tymora.
- Sentinelspire, a novel by Mark Sehestedt featuring the Fortress of Sentinelspire.
- Sentinelspire (fortress), a volcano and fortress.
- Arunika, a succubus known as the "Forest Sentinel" of the Neverwinter Wood.
- Bleucorundum, a blue dragon known as the "Sapphire Sentinel."
- Miirym, a silver dragon known as the "Sentinel Wyrm."
- "The Sentinel," the wizard tending the temple of Mystra in Elventree.
- Druid, also known as Sentinel (Heroes of the Forgotten Kingdom).
- Moonsea skysentinel, a prestige class described in Champions of Valor.
- Sentinel of Bharrai, a prestige class described in the Book of Exalted Deeds.
- Storm sentinel, a paragon path described in the Player's Handbook 2.
- Union Sentinel, a prestige class described in the Epic Level Handbook.