John Lee Mahin, (August 23, 1902 - April 18, 1984) was a prolific screenwriter and producer.

He was born in Evanston, Illinois. He worked from the 1930s to the 1970s. He worked on such films as Scarface and The Wizard of Oz.

Filmography - writer's credit

• Moment to Moment (1965)
• The Spiral Road (1962)
• North to Alaska (1960) (screenplay)
• The Barbarians (1960)
• The Horse Soldiers (1959)
• No Time for Sergeants (1958)
• Heaven Knows, Mr. Allison (1957)
• The Bad Seed (1956) (screenplay)
• Lucy Gallant (1955)
• Elephant Walk (1954)
• Mogambo (1953)
• My Son John (1952) (adaptation)
• Show Boat (1951)
• Quo Vadis (1951)
• Love That Brute (1950)
• Down to the Sea in Ships (1949)
• The Yeraling (1946) (uncredited)
• Adventure (1945) (uncredited)
• Sabotage Agent (1943)
• Tortilla Flat (1942) (screenplay)
• Woman of the Year (1942) (uncredited)
• Johnny Eager (1942) (screenplay)
• Dr. Jekyll and Mr. Hyde (1941)
• Boom Town (1940)
• The Wizard of Oz (1939) (uncredited)
• Too Hot to Handle (1938) (screenplay)
• Test Pilot (1938) (uncredited)
• The Last Gangster (1937)
• Captains Courageous (1937)
• A Star Is Born (1937) (contributing writer) (uncredited)
• Love on the Run (1936)
• The Devil Is a Sissy (1936)
• Small Town Girl (1936)
• Wife vs. Secretary (1936) (screenplay)
• Riffraff (1936) (contributor to dialogue) (uncredited)
• China Seas (1935) (contributor to screenplay construction) (uncredited)
• Naughty Marietta (1935)
• Chained (1934)
• Treasure Island (1934) (screenplay)
• Laughing Boy (1934)
• Eskimo (1933)
• Bombshell (1933) (screenplay)
• The Prizefighter and the Lady (1933)
• Hell Below (1933) (dialogue)
• Red Dust (1932) (screenplay) (as John Mahin)
• Tiger Shark (1932) (contributing writer) (uncredited)
• Scarface (1932) (continuity) (dialogue)
• The Wet Parade (1932) (adaptation) (as John L. Mahin)
• The Beast of the City (1932) (dialogue continuity) (as John L. Mahin)
• The Unholy Garden (1931) (uncredited)