"Lux Radio Theater" broadcast a 60 minute radio adaptation of the movie on
June 3, 1946 with Ethel Barrymore and June Duprez reprising their film roles.
According to a 1947 "New York Times" article, Lela E. Rogers, the mother of Ginger Rogers, denounced the script at a committee hearing of HUAC (House Committee on Un-American Activities) as a "perfect example of the propaganda that Communists like to inject" and accused Clifford Odets of being a Communist. Rogers cited the line spoken by "Ernie" to his mother, "You're not going to get me to work here and squeeze pennies out of little people who are poorer than I am," as an example of Communist propaganda. Hanns Eisler, who was nominated for an Academy Award for composing the film's score, was also interrogated by HUAC and was designated as an unfriendly witness for his refusal to cooperate.
According to an article in Hollywood Citizen-News, to secure the services of Ethel Barrymore, the studio had to pay all the expenses incurred by temporarily closing the play "The Corn Is Green", in which she was starring on Broadway.
According to an October 1943 news item in Hollywood Reporter, Alfred Hitchcock was initially slated to direct this picture.
Author Richard Llewellyn was strongly opposed to the casting of Cary Grant, demanding to know how the 40-year-old actor could play a 19-year-old character.
Ernie's full name is "Ernest Verdun Mott" - named by his father who was at the WWI battle.
This film marked a return to the big screen after an 11 year absence by star Ethel Barrymore. Prior to making this film, Barrymore had considered movie appearances an inferior art to the stage. However, her time on set, her critical acclaim, and her hefty paycheck changed her mind. After making this film, she moved from New York to California so she could concentrate on making movies instead of Broadway plays.
None but the Lonely Heart and Sylvia Scarlett were the only two films in which Cary Grant used a Cockney accent, though that was not his original accent, as he was from Bristol, which has a very different accent from London. The unique vocal intonations with which he spoke in every other film were the happy results of an unsuccessful attempt to go from an English to an American accent so that he wouldn't be limited to playing British roles in American movies.
The title of the film, None But The Lonely Heart, is taken from one of Tchaikovsky's best-known songs, which is featured in the background music.