SM or sm may refer to:
Smallpox was an infectious disease caused by one of two virus variants, Variola major and Variola minor.
A smartphone is a handheld personal computer with a mobile operating system and an integrated mobile broadband cellular network connection for voice, SMS, and Internet data communication; most, if not all, smartphones also support Wi-Fi.
Smallville is an American television series developed by writer-producers Alfred Gough and Miles Millar, based on the DC Comics character Superman created by Jerry Siegel and Joe Shuster.
SMS (Short Message Service) is a text messaging service component of most telephone, World Wide Web, and mobile device systems.
Smosh is an American sketch comedy YouTube channel created by Ian Andrew Hecox (born November 30, 1987) and Daniel Anthony Padilla (; born September 16, 1987).
A smart card, chip card, or integrated circuit card (ICC), is any pocket-sized card that has embedded integrated circuits.