While filming the scene in which Potts declares his love for Sugarpuss in a dark hotel bungalow, Gregg Toland put Barbara Stanwyck in blackface to make sure that her eyes were shining through the darkness.
Producer Samuel Goldwyn promised director Billy Wilder a $10,000 bonus if Ball of Fire (1941) became a box office hit. When the movie was released in theaters, it was an instant success. One day, Wilder stopped by Samuel Goldwyn's office and asked for his $10,000 bonus. But Goldwyn flew into a rage. "You Hungarian thief!" he shouted at Wilder. "I never promised any such thing! Get out of here!" Wilder left the office, furious. But that night, Goldwyn's wife, Helen, awoke to find him pacing the floor of their bedroom. "I've just remembered that Wilder was right," Goldwyn told her. "I *did* promise him a $10,000 bonus." "What are you going to do?" asked Helen. "What *can* I do?" Goldwyn replied. "I'm going to sit down here and write Wilder a check for $5,000!"
In the scene where Pastrami and Asthma have the professors hostage in the library, the gunmen begin shooting at random items. One gunman (Pastrami) says, "I saw me a picture last week," and proceeds to lick his thumb and then rubs it on the sight of his gun. This is a reference to star Gary Cooper's previous movie Sergeant York (1941) in which York uses this as a technique to improve his marksmanship.
To pick up authentic slang for the film script, screenwriters Billy Wilder and Charles Brackett visited the drugstore across the street from Hollywood High School, a burlesque house and the Hollywood Park racetrack.
Even though they play two of the "old men" lexicographers, Leonid Kinskey (Prof. Quintana) and Richard Haydn (Prof. Oddly) were both under 40 years old when they made this movie and, therefore, younger than Gary Cooper.
Several cast members in studio records/casting call lists for this movie were not seen in the final print. These were (with their character names): Lee Phelps (Policeman in Station), Johnnie Morris (Clerk at Justice of the Peace), Dick Rush (Policeman at Motor Inn), Del Lawrence (Irish Gardener) and Jack Perry (Fighting Bum).