SQ, Sq, or sq may stand for: Arts and entertainment Shakespeare Quarterly, a literary journal since 1950 Space Quest, an adventure video game series, 1986–1995 A fictional society in the Infinity Ring, a 2011–2015 book series SQ, a 1978 short story by Ursula K. Le Guin
Businesses and organizations Singapore Airlines (IATA:SQ) Block, Inc., a financial services company (NYSE:SQ) , a Canadian police force
Psychology Social intelligence quotient, a statistical abstraction of social intelligence Systemizing quotient, a measure of a person's neurological tendency to systemize
Science and technology SQ (program), a program for compressing files on MS-DOS and CP/M Sound quality, the characteristics of the output of a preamp, amp or sound system Stereo quadraphonic, a matrix quadraphonic gramophone record format developed by CBS Subcutaneous injection, in medicine
Other uses sq. ('square'), in a unit of area Albanian language (ISO 639-1:sq)