Debbie Reynolds and Frank Sinatra became good friends, and during production he took her to lunch and said, "Sweetie, don't get married. Don't marry a singer. We're nice guys, but we're not good husbands." At the time, Reynolds was engaged to Eddie Fisher, who ultimately left her for Elizabeth Taylor.
The original Broadway production of "The Tender Trap" by Max Shulman and Robert Paul Smith opened at the Longacre Theater on October 13, 1954, and ran for 102 performances. The original cast included Robert Preston and Kim Hunter.
At one point in the film, Charlie and Julie watch a movie clip (on TV) from Easy to Love (1953), with Esther Williams and John Bromfield. That movie was filmed in Technicolor but broadcast on TV in B&W, as most of films were at that time. However, MGM did not release that particular title to TV until nearly a decade later; the MGM film library, which was finally released to television in the Fall of 1956, did not include any titles filmed after 1948.
In the recording on TV of Sylvia performing on violin, the orchestra is playing Pyotr Ilyich Tchaikovsky's "1812 Overture."