SQR may refer to:
Biochemistry Succinate-Q reductase, an enzyme complex sulfide:quinone oxidorreductase pathway, see Microbial oxidation of sulfur
Computing SQR, a programming language SQR codes, Secure Quick Response codes
Linguistics Siculo-Arabic (ISO 639 language code: sqr) Smiting-blade symbol (hieroglyph)
Mathematics square (algebra) (sqr, sq) square root (sqr, sqrt)
Transportation Soroako Airport (IATA airport code SQR) Soroako, South Sulawesi, Indonesia Alsaqer Aviation (ICAO airline code SQR) defunct Libyan airline, see List of airline codes (A) Sultanpur Lodi (Indian rail code SQR), see List of railway stations in India
Other uses The SQR Store, originally "S.Q.R.", department store in Anaheim, California, 1907–1978
See also
Square (disambiguation)