Arthur Julius Marx (July 21, 1921 – April 14, 2011) was an American author, a former nationally ranked amateur tennis player, and son of entertainer Groucho Marx, and his first wife, Ruth Johnson. He is named after Groucho's brother Arthur "Harpo" Marx.

Marx spent his early years accompanying his father around vaudeville circuits in the United States and abroad. When he was 10, the family moved to Southern California, where the Marx Brothers continued their film careers.

Tennis career

Marx was a nationally ranked tennis player before he was 18. While he was attending the University of Southern California, he won the National Freshman Intercollegiate Tennis title at Montclair, New Jersey.

At the Cincinnati Masters, Marx reached the singles final in 1941 before falling to Bobby Riggs. To reach the final, Marx knocked off future International Tennis Hall of Fame member John Doeg in the round of 16, Frank Froehling in the Quarterfinals, and Gardner Larned in the Semifinals. Riggs had blown through his competition to reach the final, and Marx gave him his toughest test of the tournament, stretching the future Hall of Famer to five sets before falling, 11-9, 6-2, 4-6, 6-8, 6-1.

Literary, radio, and TV career

After his time as a tournament tennis player and four years in the United States Coast Guard during World War II, 16 months of which were spent in the South Pacific, he worked as an advertising copywriter, a radio gag man for Milton Berle, and a writer of Hollywood movies, Broadway plays and TV scripts for such hit shows as My Three Sons, All in the Family, and Alice. He and his collaborator, Robert Fisher, were head writers for Alice and wrote 40 episodes of that show. Marx was also co-creator of the TV series Mickey starring Mickey Rooney.

Along with Fisher, he co-authored The Impossible Years, which ran for three seasons on Broadway and starred Alan King; Minnie's Boys, a musical about the Marx Brothers' vaudeville years that starred Shelley Winters; My Daughter's Rated X, which won the Straw Hat award for best new comedy on the summer stock circuit, and Groucho: A Life in Revue, which won great critical acclaim and was nominated for a New York Outer Critics Circle award for best play and London's Laurence Olivier Award for Comedy Production of the Year.

On his own, Marx wrote 12 books, including The Ordeal of Willie Brown (1951), Not as a Crocodile (1958), Goldwyn: A Biography of the Man Behind the Myth (1976), Red Skelton (1979), The Nine Lives of Mickey Rooney (1988), The Secret Life of Bob Hope and the tennis-themed murder mystery Set to Kill (both 1993). His 1974 book on Dean Martin and Jerry Lewis entitled Everybody Loves Somebody Sometime (Especially Himself) was adapted into the 2002 made-for-television movie Martin and Lewis.

Marx also wrote several books featuring different takes on his relationship with his father, including Life with Groucho (1954), Son of Groucho (1972), My Life With Groucho (1992), and Arthur Marx’s Groucho: A Photographic Journey (2001).