Dei or DEI may refer to:
- DEI, a common initialism for diversity, equity, and inclusion.
- Dei, the genitive singular of Deus , the Latin word for "god" or "deity".
- Darrell Edward Issa, U.S. representative from California
- DEI (Dabney Eats It), motto of Dabney House at California Institute of Technology
- Dei Rural LLG, a local government in Papua New Guinea
- Benedetto Dei (1417–1492), Italian poet and historian
- Destroy Erase Improve , 1995 extreme metal album by Meshuggah
- Divide et impera
- Doofenshmirtz Evil Incorporated, a fictional company in the Phineas and Ferb animated TV series
