SUP
- SUP Media
- Sailors' Union of the Pacific
- Saskatchewan United Party
- Scottish Unionist Party (1986)
- Sfermion
- Simple Update Protocol
- Singapore United Party
- Socialist Unity Party (disambiguation)
- Societas unius personae
- Software Upgrade Protocol
- Standup paddleboarding
- Stanford University Press
- Subscript and superscript
- Supangle
- Super (disambiguation)
- Supper
- Supremum
- Sydney University Press
- Syracuse University Press
- Syriac Union Party (disambiguation)
- What's Up (disambiguation)