A Nereid is a sea nymph in Greek mythology.

Nereid or Nereids may also refer to:

• Nereid (moon), the third-largest moon in the Neptune system
• Nereid (worm), a polychaete worm
• Nereids (organization), a fictional organization in the anime series Daphne in the Brilliant Blue
• The Nereids, a lost tragedy by the Greek playwright Aeschylus assigned by modern scholars to the trilogy the Achilleis
• Nereid Avenue (IRT White Plains Road Line), a station of the New York City Subway
• Nereid Avenue, a major street in the Wakefield section of The Bronx, New York City
• Nereid (Dungeons & Dragons), fey beings similar to nymphs and dryads

• French ship Néréide
• HMS Nereide
• Nereide (horse)
• Neriad Horseshoe Bat, a species of bat
• Nereida
• Nereidi, a sculpture in Helsinki, Finland