SQ, Sq, or sq may stand for:

  • Sentience quotient, a measure of the total processing capacity of a brain
  • Singapore Airlines IATA airline designator
  • Sound quality, the characteristics of the output of a preamp, amp or sound system
  • Space Quest, a series of adventure games by Sierra Entertainment
  • Spiritual quotient, a term in popular psychology
  • sq, the ISO code for the Albanian language (ISO 639 alpha-2)
  • SQ (program), a program for compressing files on MS-DOS and CP/M
  • Square, a type of measure of area, such as square foot (sq ft)
  • Stereo quadraphonic, a matrix quadraphonic gramophone record format developed by CBS
  • Subcutaneous injection, an abbreviation based on pronunciation
  • Sûreté du Québec, the Quebec police force
  • Systemizing quotient, a measure of a person's neurological tendency to systemize