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.
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.
ETR 500 (Elettro Treno Rapido 500) is a family of Italian high-speed trains introduced in 1993.