AR-15 refers to any of several rifles:
- ArmaLite AR-15, a selective-fire rifle manufactured by ArmaLite, and predecessor of the United States military M16 rifle.
- Colt AR-15, a line of semi-automatic rifles manufactured by Colt, based on the United States military M16 rifle.
- AR-15 variants, a general category of AR-15 clone firearms based on the Colt AR-15 design. (Colt owns the AR-15 trademark, but not the generic design. Hence, the reason that the AR-15 variant name is used.)