ASG may refer to:
- ASG, a band
- ASG Software Solutions
- Abstract semantic graph
- Abu Sayyaf Group
- Airsoft gun
- All Saints Greek Orthodox Grammar School, or All Saints Grammar
- All-star game
- Alsager railway station's national rail code
- Alternating step generator, a cryptographically secure pseudorandom number generator
- AS Gien, French association football club
- IATA code for Ashburton Aerodrome, New Zealand
- Asymptotic giant branch, a phase of stellar evolution
- Australasian Seabird Group, a special interest group of Birds Australia
- Australian Standard Garratt, a WWII-era Australian steam-engine locomotive
- Austria Switzerland Germany, a geographic region used by companies to name the predominately German speaking countries in Europe
- Labour and Social Justice – The Electoral Alternative (Arbeit & soziale Gerechtigkeit)
- Atlanta Spirit, LLC, aka Atlanta Spirit Group, the owners of the Atlanta Hawks and the operating rights to Philips Arena