FS, fS or fs may refer to:
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 is a professional Latvian football club located in Riga, Ķekava. As of 2012 they play in the Latvian Higher League.
The fstab (or file systems table) file is a system configuration file commonly found at /etc/fstab on Unix and Unix-like computer systems.
ETR 500 (Elettro Treno Rapido 500) is a family of Italian high-speed trains introduced in 1993.
The system utility fsck (for "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 and macOS.