AG may stand for:
- Aargau (Swiss canton)
- Air-to-Ground
- Aktiengesellschaft (German: corporation, company limited by shares)
- Algeria (FIPS country code)
- Antigua and Barbuda (ISO country code)
- Arabian Gulf
- Artificial gravity
- Assembly of God church
- Attogram
- Attorney General
- Silver (Ag, symbol for the chemical element argentum)
- the US Navy hull classification symbol for Auxiliary General