While Spencer Tracy and Jean Harlow play an engaged couple in this film, it was Harlow and William Powell who were contemplating marriage off screen during production. Unfortunately, Harlow would die the following year, before she and Powell could wed. She was only 26 years old.
Reportedly, while shooting the movie, the four stars had become close friends, and William Powell even gave up his old habit of hiding out in his dressing room between scenes so he could join in the fun with the rest of the cast. One of the biggest jokes was a running gag Spencer Tracy played on Myrna Loy, claiming that she had broken his heart with her recent marriage to producer Arthur Hornblow Jr. He even set up an "I Hate Hornblow" table in the studio commissary, reserved for men who claimed to have been jilted by Loy.
William Powell and Myrna Loy also co-starred in Il paradiso delle fanciulle (1936), another of the Best Film Oscar nominees that year.
Myrna Loy recalled in her 1987 autobiography that a good time was had by all during the shoot - "Libeled Lady was one of the best of the so-called screwball comedies, with a great cast, and Jack Conway directing us at breakneck speed." She praised her co-stars and also expressed her love for working with Walter Connolly, whom she described as "darling."