PSF is a three-letter abbreviation or three-letter acronym (TLA) that may stand for:
- Point spread function
- Private sector forestry
- Pounds per square foot
- Price per square foot
- Penile scrotal fusion
- Python Software Foundation
- Protein Structure Factory
- Prolate spheroidal function
- Police Suicide Foundation
- Pharmaciens sans Frontières
- Perfect Storm Foundation
- Piano Santa Foundation
- Pacific Salmon Foundation
- Planetary Studies Foundation
- Proteus Syndrome Foundation
- Phelps-Stokes Fund
- Permanent School Fund
- Plastic Surgeons Forum
- PlayStation Sound Format