IS1, IS-1, or variation, may refer to:
IS1 IS1 may refer to: HMG Infosec Standard No.1, a computer security standard used in the UK The IBM IS1, an early relational database system
IS-1 IS-1 may stand for: The Soviet tank IS-1 the first model of the Soviet Iosif Stalin tank series The first model of the Soviet Istrebitel Sputnikov missile; see anti-satellite weapon Nikitin IS-1, a retractable wing fighter aircraft
See also ISI (disambiguation) IS (disambiguation)