Thu and variations may refer to:
- Thursday
- Thu (surname), the Gan romanization of the Chinese surname Su
- Thu (pronoun) or Þu, an Old English pronoun
- Thû, an early name for Sauron in J.R.R. Tolkien's works
- Thu, Palpa, a village development committee in Nepal
- Thu., abbreviation for the orchid genus Thunia
- Thu, a dog belonging to the Claidi and Argul in The Claidi Journals by Tanith Lee
- Thu, a nation on the fictional planet Urras in the novel The Dispossessed by Ursula K. Le Guin
- Tsinghua University in China
- Thule Air Base (IATA airport code)