The Mercury Summer Theatre of the Air (1946) is a CBS radio drama series produced, directed by and starring Orson Welles.

It harked back to Welles's earlier The Mercury Theatre on the Air (1938) and its successor, The Campbell Playhouse, but was not able to replicate its success.

Nonetheless, the expensive production flopped, and in a bid to give it publicity, Welles broadcast a half-hour condensation of the musical.

Welles had created, directed and starred in a string of radio drama series since 1937, and The Mercury Summer Theatre of the Air in 1946 ended up being his last.

He moved to Europe in the fall of 1947, and his later radio work was made in Britain, most notably The Adventures of Harry Lime (1951–52).