SEU or Seu may refer to:
- A single event upset is a change of state caused by a high-energy particle strike to a micro-electronic device
- slightly enriched uranium, a very low enrichment of uranium to 0.9% to 2% 235U.
- subjective expected utility is a way to make decisions in the presence of risk
- Shoot_'em_up, a video game sub-genre
- Social Exclusion Unit, a British Government task force to address social exclusion
- Southeastern University (disambiguation)
- Southeastern University (Florida), a private, non-profit university
- Southeastern University (Washington, D.C.), formerly a private, non-profit university
- St. Edward's University is a private, Catholic university in Austin, Texas
- Southeast University (Bangladesh), a private, non-profit university in Banani, Dhaka, Bangladesh
- Southeast University, a university in Nanjing, Jiangsu Province, China
- La Seu, a common name for Cathedrals in Catalan