Garson Kanin wrote that Marilyn Monroe made a screen test for this film in 1948 before signing a two-picture contract. Those who saw it thought it was excellent, but Columbia head Harry Cohn did not take the trouble to walk six steps from his desk to his projection room to watch it.
In his autobiography, Garson Kanin wrote that Harry Cohn paid the record $1 million for the films rights because he had heard that Kanin said he "wouldn't sell the rights to Harry Cohn for any amount - not even a million dollars."
The part of Billie Dawn was written by Garson Kanin for Jean Arthur. A couple of nights before the play was due to open, Arthur abruptly dropped out and Judy Holliday was drafted in. Arthur was briefly considered for the film version, but turned the part down. A move to loan out Lana Turner from MGM for the role of Billie Dawn was later abandoned.
Judy Holliday won the Academy Award for Best Actress for her performance in the film. In contrast, Melanie Griffith, who plays Billie Dawn in the remake, Born Yesterday (1993), was nominated for the Razzie Award for Worst Actress. She failed to win, however.
To help facilitate shooting, George Cukor decided to rehearse Born Yesterday (1950) as if it were still a stage play. For two weeks, the cast worked on their lines while a construction crew built a 300-seat mini-theater within one of the studio's sound-stages. It was there that Judy Holliday, William Holden and Broderick Crawford gave six performances in front of a live audience so that Cukor could precision-time the pacing of the film's jokes.
Harry Cohn, the head of Columbia, paid $1 million for the film rights, intending it to be a vehicle for his hottest female star, Rita Hayworth. His star, however, wasn't interested as she'd just married Prince Aly Khan. One thing Cohn didn't want was for Judy Holliday to reprise her Broadway role. He relented when he saw how effectively George Cukor used her in Adam's Rib (1949).
Paul Douglas, who created the role of Harry Brock on stage, turned down the chance to play him in the movie adaptation because the part had been considerably reduced for the film. He later went on to star opposite Judy as Edward L. McKeever in the 1956 film, The Solid Gold Cadillac (1956) where Judy once again plays a ditsy blonde who ends up outsmarting her opponents.
George Cukor instructed production designer Harry Horner to approach the script as if it had never been a stage play. Instead of the play's one-room set, Horner constructed an entire hotel suite, allowing Cukor to move the action from room to room as the action would have dictated in real life.
During location shooting in Washington, George Cukor was so moved by the sight of the Jefferson Memorial, that he insisted on having Judy Holliday and William Holden visit it during their tour of the city.
After reading and working on the Albert Mannheimer screenplay, George Cukor met with Harry Cohn to get his permission for Garson Kanin to rewrite the film's screenplay. Cukor felt the Mannheimer screen play's dialogue was missing the rhythm and tempo between Billie Dawn and Harry Brock in the original Broadway stage property. Kanin's rewrite was used instead of the original Mannheimer screen play adaptation.
Judy Holliday had a hard time adjusting to filming the play without an audience. Although the crew often laughed during rehearsals, she had to play the scenes to total silence. Critics would later complain that some of the dialogue was so quickly paced that audience laughter drowned out lines.
Used to the honeyed tones of the typical Hollywood leading lady, the sound department tried to clean up the sound of Judy Holliday's voice. When George Cukor watched the first rushes, he complained that her voice sounded different. The sound engineer told him "We just cut out some of the crud in her lower register." Cukor told them to stop because "You've also cut out the comedy and the heart."
When production ended, Judy Holliday stayed in town for some interviews, then returned to the East where she and her husband, classical musician David Oppenheim, had bought a country home near West Point.