315 may refer to:

315 (year) 315 BC, a calendar year 315 (number), the natural number following 314 and preceding 316 Project 315, a nonprofit in Israel NGC 315, an elliptical galaxy 315th Operations Group, a military unit 315th Air Division, a military unit 315th Airlift Wing, a military unit 315th Cyberspace Operations Squadron, a military unit 315th Rifle Division (Soviet Union), a former military unit 315th Fighter Squadron, a military unit 315 Constantia, a main-belt asteroid 315 series, a Japanese train type NCR 315, a 1962 second-generation computer

See also 315th (disambiguation)