Sym may refer to:
- S'ym, comic book character
- Sım, Azerbaijan
- Sym (river), a left tributary of the Yenisey with a portage to the Vakh (Ob basin)
- The symmetric group on a set X, denoted Sym(X)
- The symmetrization linear operator
- Karol Juliusz "Igo" Sym, an Austrian-born Polish actor and collaborator with Nazi Germany.
SYM may refer to:
- IATA code for Pu'er Simao Airport, Yunnan, China
- Sanyang Motor, Taiwanese maker of motorcycles and scooters
- the SYM-1, a single board "trainer" computer produced by Synertek
- N=4 supersymmetric Yang-Mills theory, a model of particles in mathematics and theoretical physics.
- Switzerland Yearly Meeting of the Religious Society of Friends (Quakers)
- Military/US Navy Code for commonly used equipment. example: Symbol 2842 [SYM 2842] - Jackbox, Sound-Powered Telephone.