Inspired by the real-life story of husband-and-wife lawyers William Dwight Whitney and Dorothy Whitney, who represented Raymond Massey and his ex-wife Adrienne Allen in their divorce. After the Massey divorce was over, the Whitneys divorced each other and married the respective Masseys.
In the scene in which Amanda is driving Adam to work, he tells her, "Oh, you're giving me the Bryn Mawr accent". Bryn Mawr College was Katharine Hepburn's alma mater, where she claimed to have gained her distinctive voice.
Katharine Hepburn reportedly urged director George Cukor to focus the camera on Judy Holliday during a number of their shared scenes, not only because she was a fan of the new-to-movies Holliday but because it was hoped the studios would see how terrific Holliday was and cast her as the lead in Born Yesterday (1950), the role she'd created on Broadway. It worked.
Katharine Hepburn, George Cukor and Garson Kanin managed to turn Judy Holliday's performance into a screen test for Born Yesterday (1950). In particular, one long scene in which Doris recounts how and why she shot her husband was written as a near monologue for the character. Holliday shot her close-up of the speech in one take. Then Hepburn refused to shoot more than a few brief reaction shots, thus forcing Cukor to focus the entire scene on Holliday. That scene convinced Cohn to test Holliday. After three tests (she borrowed a gown from Hepburn for one of them), he finally cast her over such glamorous stars as Rita Hayworth, Lucille Ball and the young Marilyn Monroe. Hepburn would later explain her generosity to Kanin: "It was the kind of thing you do because people have done it for you."
The script called for Kip Lurie to write a song about his devotion to Amanda. Garson Kanin wrote a song for the moment, but nobody liked it. When he dared Katharine Hepburn to find a better song, she asked Cole Porter to do it. At the time, the leading lady's name was "Madeleine." Porter turned Hepburn down, saying it was impossible to do a song about a woman with that name. Then he suggested changing her name to Amanda. Eight days later, he presented them with a new song, "Farewell, Amanda." It was actually a re-working of "So Long, Samoa," a song he had written in 1940 and never used. Rather than charge MGM for his services, he asked that they make a large donation to the Red Cross.
During filming, Katharine Hepburn and Spencer Tracy stayed in separate homes, as was their habit whenever travelling together. That allowed them to maintain their decades-long relationship without any scandal appearing in the press.
Judy Holliday hoped to repeat her stage performance in Born Yesterday (1950), but the rights had been bought by Columbia Pictures, whose production chief, Harry Cohn, wanted no part of the woman he referred to as "that fat Jewish broad." He wouldn't even let her test for the role. When Garson Kanin complained about this to Katharine Hepburn, she suggested casting Holliday as Doris Attinger. When they offered her the role, however, she turned it down. Finally Hepburn got the real reason out of her. Sensitive about her weight, Holliday didn't want to be called "fatso" on screen. Hepburn assured her that the Kanin's would gladly rewrite the line: "They're writers. They know lots of words." Finally, Holliday agreed. Later she insisted that the word "fatso" be restored because it was the best way of playing the scene.
Judy Holliday was so nervous on her first day of shooting that she repeatedly missed her mark. Fearing the crew would think her stupid, she offered them all free tickets to see her in "Born Yesterday".
In the memorable Spencer Tracy-Katharine Hepburn massage scene, a radio plays Frank Sinatra singing Cole Porter's "Farewell, Amanda," a gift to Amanda Bonner (played by Hepburn) from her songwriter-neighbor, Kip Lurie (played by David Wayne) who, earlier in the picture, had crooned the ditty, accompanying himself on the Bonners' piano. While Adam Bonner (played by Tracy) is massaging his wife, he abruptly shuts off the radio. Sinatra is again heard when a record is accidentally started in a later scene. This prerecording of "Farewell, Amanda" is lost.
Shooting in New York meant that Judy Holliday could continue appearing on Broadway in "Born Yesterday". At times she had to work a 20-hour day to honour her commitments to both projects. When production moved back to Hollywood, however, she had to arrange an early release from her Broadway contract.
During filming, Katharine Hepburn was planning to tackle feminism a la Shakespeare as the cross-dressing Rosalind in a revival of As You Like It. George Cukor hoped to direct her in the production, but, wanting to make the revival an escape from Hollywood, she asked the producer to turn him down gently. He got word during the first week of filming. The stage production was a personal triumph for her.
The Production Code Administration's chief concerns with the film were that the judicial system be treated with proper respect and nothing be done to make the adulterous relationship between Warren and Doris funny. They also cautioned against making Amanda's songwriter friend, Kip, come across as gay.
When Tom Ewell is walking to his girlfriend's apartment at the beginning of the film, he is whistling "You Are My Lucky Star". This song is also featured in Singin' in the Rain (1952) which stars the same actress who plays Tom Ewell's girlfriend, Jean Hagen.
During the movie screening of 'The Mortgage the Merrier' where the Bonners are shown with the new house and dogs, they do 'tree kissing' and 'barn kissing' which were the Old Connecticut customs as told by Kip Lurie ('David Wayne') in the movie. Katharine Hepburn who plays Amanda Bonner happens to be from Connecticut.