SQ, Sq, or sq may stand for:
Psychology:
- Social (intelligence) quotient, a statistical abstraction of social intelligence
- Systemizing quotient, a measure of a person's neurological tendency to systemize
Other uses in 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:
- Shakespeare Quarterly, a quarterly academic journal on the works of William Shakespeare
- Shqip, an Albanian language (ISO 639 alpha-2 code "sq")
- Singapore Airlines (IATA airline designator SQ)
- Space Quest, a series of adventure games by Sierra Entertainment
- Square, a type of measure of area, such as square foot (sq ft)
- Square, Inc., financial services company (NYSE stock ticker SQ)
- Status quo, Latin for "current situation"
- Supplier Questionnaire (SQ), similar to a Pre-Qualification Questionnaire, used in conjunction with an invitation to tender
- Sûreté du Québec, the Quebec police force
- An organization from the Infinity Ring book series