Ehrenfest is a surname which may refer to:
- Paul Ehrenfest, a Jewish Austrian physicist and mathematician
- Ehrenfest equations
- Ehrenfest model
- Ehrenfest paradox and Ehrenfest theorem, named after him
- Ehrenfest theorem
- 32796 Ehrenfest
- Tatjana Ehrenfest-Afanassjewa, a Ukrainian-Russian mathematician, wife of Paul
- Tanja van Aardenne-Ehrenfest (1905–1984), an Austrian Dutch mathematician, daughter of Paul