Astra Digital Radio (ADR) was a system used by SES for digital radio transmissions on the early Astra satellites, using the audio subcarrier frequencies of analogue television channels.

ADR ceased on 30 April 2012 when analogue broadcasts on Astra 19.2°E ended.

The carrier was digitally modulated and carried a 192 kbit/s, 48 kHz sampled MPEG-1 Layer II (MP2) encoded signal.

ADR was succeeded by DVB-S, with which it is incompatible, despite both being transmitted using MP2 and generally at the same bitrates.

As a result, when the final analogue switch-off on the Astra 1 satellites occurred, ADR became obsolete.