SG1 commonly refers to Stargate SG-1, a television show.
SG1 may also refer to:
- SG1 (or SG/1), a version of the Heckler & Koch G3 rifle
- SG1, a minor planet notation indicating the thirty-third discovery in late September of a given year, see provisional designation in astronomy
- 1941 SG1, the asteroid 1546 Izsák
- 1955 SG1, the asteroid 4300 Marg Edmondson
- 1973 SG1, the asteroid 14792 Thyestes
- 1974 SG1, the asteroid 2756 Dzhangar
- 1987 SG1, the asteroid 6474 Choate
- 1989 SG1, the asteroid 7934 Sinatra
- 1992 SG1, the asteroid 7250 Kinoshita
- Scanlan SG-1, a glider
- Schlachtgeschwader 1, a German Luftwaffe unit during World War II
- SG1 postcode district, in the SG postcode area, in Stevenage in the United Kingdom