SFSR (disambiguation)
SFSR may refer to:
- A Soviet Federative Socialist Republic or Socialist Federative Soviet Republic, any of several Republics of the Soviet Union: 
- Russian Soviet Federative Socialist Republic (Russian SFSR) (1917–1991)
 - Transcaucasian Socialist Federative Soviet Republic (Transcaucasian SFSR) (1922–1936)
 
 - Santa Fe Southern Railway, a short line railroad in New Mexico, United States
 - San Francisco Syncope Rule, a clinical prediction rule for syncopal episodes