Brown had major roles in several popular radio shows: He was "John Doe" in the Texaco Star Theater's version of Fred Allen's Allen's Alley,[2] played Irma's love interest Al in My Friend Irma, both "Gillis" and Digby "Digger" O'Dell in The Life of Riley, (a role he reprised for the first incarnation of the television show), "Broadway" in The Damon Runyon Theatre, and "Thorny" the neighbor on the radio version of The Adventures of Ozzie and Harriet. Perhaps his most memorable piece of work is the ‘Broadway’ role; once heard, many find it impossible to think of the narrator of Damon Runyon’s stories as anyone else. It was a measure of Brown’s talent that this quintessentially American character was portrayed by an Englishman.
Brown appeared in some notable films: as the inebriated professor in Hitchcock’s Strangers on a Train (1951), The Day the Earth Stood Still (1951, uncredited), and The Wild One (1953); he supplied the voice of "Ro-Man" in the 1953 cult science fiction B-film Robot Monster.