In J. R. R. Tolkien's fictional Middle-earth, Tol Eressëa is a large island. Its name may be translated from Elvish as the Lonely Island, for it lay originally in the middle of the ocean Belegaer, far from any other landmasses.

Ulmo pushed it back and forth across Belegaer twice to transport the Elves to Aman. After that, it came to rest forever just off the eastern shore of that continent, and was inhabited by the Teleri.