Dunay radar was a system of two Soviet radars used to detect American ballistic missiles fired at Moscow. They were part of the A-35 anti-ballistic missile system. One sector of one of the radars, the Dunay-3U is still operational and is run by the Russian Space Forces as part of the Main Control Centre of Outer Space.

The A-35 anti-ballistic missile system was a Soviet military anti-ballistic missile (ABM) system deployed around Moscow to intercept enemy ballistic missiles targeting the city or its surrounding areas. The A-35 was the only Soviet ABM system allowed under the 1972 Anti-Ballistic Missile Treaty. In development as of the 1960s and in operation from June 1972 until the 1990s, it featured the nuclear-armed A350 exoatmospheric interceptor missile. The A-35 was supported by two Dunay radars and the Soviet early warning system. It was followed by the A-135 in the early 1990s.