Lewy may refer to:
- Levi, a biblical personage.
- Lewy body, abnormal aggregates of protein that develop inside nerve cells of the brain.
- Dementia with Lewy bodies, progressive brain disease associated with degenerative dementia in the elderly.
- Alfred J. Lewy, Psychiatrist.
- Bergnart Carl Lewy, Danish chemist.
- Casimir Lewy, Philosopher.
- Frederic Lewy, Neurologist best known for discovering Lewy bodies.
- Glen Lewy, National Chair of the Anti-Defamation League.
- Guenter Lewy, Controversial Political Scientist, University of Massachusetts.
- Hans Lewy, Mathematician.
- Israel Lewy, German-Jewish scholar.
- Peter Lewy, Cellist.
- Robert Ira Lewy, American doctor noted for research on aspirin therapy in heart disease and allergic reaction to silicone breast implants.