Nemesis has several meanings:
- The Greek goddess of divine retribution, see Nemesis (mythology)
- A play by Alfred Nobel, see Nemesis (Nobel)
- A hypothetical companion star of the Sun, see Nemesis (star)
- A science fiction novel written by Isaac Asimov, see Nemesis (Asimov)
- A detective novel by Agatha Christie, see Nemesis (Christie)
- A "Star Trek" movie released in 2002, see Star Trek: Nemesis
- An operating system designed by University of Cambridge, University of Glasgow, Swedish Institute of Computer Science and Citrix Systems, see Nemesis (computing)
- A comic published in 2000 A.D, see Nemesis the Warlock
- A name used for some instalments of the Gradius videogame series, mainly in Europe