PSF is a three-letter abbreviation or three-letter acronym (TLA) that may stand for:
- French Social Party (Parti Social Français)
- French Socialist Party (Parti Socialiste Français)
- Palestinian Popular Struggle Front
- Pennsylvania Shakespeare Festival
- Peoples Students Federation
- Pharmaciens Sans Frontières
- Phelps-Stokes Fund
- Physical Storage Format a data format for navigation data
- Pittsfield Municipal Airport (IATA airport code: PSF)
- Point spread function
- Portable Sound Format
- Posterior Spinal fusion
- Pounds per square foot, a measure of pressure; see also Pounds per square inch
- Premium Standard Farms, Inc
- Pressed Steel Fisher
- Price per square foot
- Progressive segmented Frame
- Prolate spheroidal wave functions
- Protein Segment Finder
- Protein structure file for molecular dynamics, a Chemical file format
- Provisional Sinn Féin
- Public Security Forces the Bahraini principal law enforcement arm of the Ministry of Interior.
- Python Software Foundation
- P.S.F. Records, a record label