FS, fS or fs may refer to:
The fstab (or file systems table) file is a system configuration file commonly found at /etc/fstab on Unix and Unix-like computer systems.
The FSO Polonez was a Polish motor vehicle that was produced from 1978 to 2002. The car's name comes from the Polish dance, polonaise.
Free Software Foundation (FSF) grants two annual awards. Since 1998, FSF has granted the award for Advancement of Free Software and since 2005, also the Free Software Award for Projects of Social Benefit.
ETR 500 (Elettro Treno Rapido 500) is a family of Italian high-speed trains introduced in 1993.
FK Metta (also FK Metta/Latvijas Universitāte) is a professional Latvian football club in Riga. As of 2012 they play in the Latvian Higher League.
The system utility fsck (file system consistency check) is a tool for checking the consistency of a file system in Unix and Unix-like operating systems, such as Linux, macOS, and FreeBSD.