Thomais may refer to:
- Thomais of Alexandria, Byzantine martyr and 5th century saint
- Thomais of Lesbos (c. 909/913 - 947/951), Byzantine laywoman and saint
- Thomais Orsini (born c. 1330), queen consort of Epirus and Thessaly
- Thomaïs Emmanouilidou (born 1997), Greek rower