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