Radio Amateur Satellite Corporation - an amateur radio organization promoting and developing amateur radio satellite service. Over two dozen satellites are now in operation, many as a result of AMSAT effort.

AMSAT is a name for amateur radio satellite organizations world-wide, but in particular the Radio Amateur Satellite Corporation (AMSAT-NA) with headquarters at Silver Spring, Maryland, near Washington DC. AMSAT organizations design, build, arrange launches for, and then operate (command) satellites carrying amateur radio payloads, including the OSCAR series of satellites. Other informally affiliated national organizations exist, such as AMSAT Germany (AMSAT-DL) and AMSAT Japan (JAMSAT).