SP may stand for:
- São Paulo
- Saskpower (Canada)
- secondary power
- service pack
- Shore patrol (US Navy)
- short perforation (philately)
- signal processor
- Silver piece (role-playing games)
- South Park
- Southern Pacific Railroad
- South Pole
- stack pointer (computers)
- state park (US)
- state police (US)
- Suppressive Person - in the Church of Scientology, formally a condemned and shunned heretic or wrongdoer, loosely used to describe a source of trouble
- Political parties:
- Socialist Party or Social Democratic Party
- Samata Party (India)
- Saskatchewan Party
- Schleswigsche Partei