LSF may refer to:

Science and technology

• IBM Spectrum LSF, a software job scheduler formerly called Platform LSF

• Laser-stimulated fluorescence, a spectroscopic method

• Late SV40 factor, a protein

• Lightweight steel framing, a building material

• Line spectral frequencies, in signal processing

• Line spread function, in optics

Organisations

• Financial Security Law of France ()

• Ledøje-Smørum Fodbold, an association football club in Denmark

• Libre Space Foundation, a Greek non-profit space exploration foundation

• , a Film Censorship Board of Indonesia

Other uses

• French Sign Language ()

• Latino sine flexione, a constructed language

• "L.S.F." (song) or "L.S.F. (Lost Souls Forever)", by Kasabian

• Law Society's Final Examination, replaced by the Legal Practice Course, UK

• Liberty Security Force, a faction in the video game Freelancer