661 Cloelia is a minor planet orbiting the Sun that was discovered by American astronomer Joel Hastings Metcalf on February 22, 1908. Cloelia is a member of the dynamic Eos family of asteroids that most likely formed as the result of a collisional breakup of a parent body. The planet is named after the Ancient Roman woman Cloelia. The name may have been inspired by the asteroid's provisional designation 1908 CL.