The R-33 (Russian: Вымпел Р-33, NATO reporting name: AA-9 Amos) is a long-range air-to-air missile developed by Vympel.

It is the primary armament of the MiG-31 interceptor, intended to attack large high-speed targets such as the SR-71 Blackbird, the B-1 Lancer bomber, and the B-52 Stratofortress.

It uses a combination of semi-active radar homing for initial acquisition and mid-course updates, and inertial navigation to reach the target at extreme range.

The Zaslon phased array radar of MiG-31 allows six missiles to be guided simultaneously at separate targets.

Two prototypes were built in 1968, featuring nose-mounted manoeuvring fins and intended for carriage on underwing pylons, similar to the Bisnovat R-40 on board the MiG-25.

The space on board the passenger aircraft-based testbed allowed for the carriage of extensive diagnostic and support equipment.

The final decision was made in favor of semi-active radar homing with an inertial initial stage.

A small run of one dummy (for launch system testing), 5 'programmed' (guidance and propulsion only, no warhead) and 8 fully functional trial missiles were built to the new design before the end of 1972.