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.
San Francisco businessman Harry Graham and his wife and business partner, Eve, are in the process of adopting a child. When private investigator Mr. Jordan uncovers the fact that Graham has another wife, Phyllis, and a small child in Los Angeles, he confesses everything.
A young woman is hired to take care of an eerie old mansion, where she finds herself entangled with an enigmatic murderer.
Ro-Man, an alien robot who greatly resembles a gorilla in a diving helmet, is sent to earth to destroy all human life. Ro-Man falls in love with one of the last six remaining humans, and struggles to understand how his programming can instruct him to kill her while his heart demands that he can't.
An alien and a robot land on Earth after World War II and tell mankind to be peaceful or face destruction.
Having met on a train, a smooth-talking psychotic socialite shares his theory on how two complete strangers can get away with murder to an amateur tennis player — a theory he plans to test out.
An investigator from the War Crimes Commission travels to Connecticut to find an infamous Nazi, who may be hiding out in a small town in the guise of a distinguished professor engaged to the Supreme Court Justice’s daughter.