The first of only three films to win every major Academy Award, including Best Picture.
The locomotive that holds up Peter Warne, supposedly in New Jersey, is a Southern Pacific 2-6-0 Mogul, number 1662, class M-4, built by the Cooke Works of the American Locomotive Company, commonly known as ALCO.
This was the first film to win the Oscar "grand slam" (Best Picture, Best Actor, Best Actress, Best Director and Screenplay).
Was the first film to win both the Academy Award and National Board of Review Award for the Best Picture.
When Clark Gable showed up for work on the first day, he reportedly said grimly, "Let's get this over with."
When director Frank Capra asked Claudette Colbert to expose her leg for the hitchhiking scene, she at first refused. Later, after having seen the leg of her body double, she changed her mind insisting that "that is not my leg!"
While shooting the scene where he undresses, Clark Gable had trouble removing his undershirt while keeping his humorous flow going and took too long. As a result the undershirt was abandoned altogether. It then became cool to not wear an undershirt which resulted in a large drop in undershirt sales around the country. Legend has it that in response, some underwear manufacturers tried to sue Columbia.
A persistent legend has it that Gable had a profound effect on men's fashion, thanks to a scene in It Happened One Night. As he is preparing for bed, he takes off his shirt to reveal that he is bare-chested. Sales of men's undershirts across the country allegedly declined noticeably for a period following this movie.
Bugs Bunny's nonchalant carrot-chewing standing position, as explained by Chuck Jones, Friz Freleng, and Bob Clampett, originated in a scene in the film It Happened One Night, in which Clark Gable's character leans against a fence, eating carrots rapidly and talking with his mouth full to Claudette Colbert's character. This scene was well known while the film was popular, and viewers at the time likely recognized Bugs Bunny's behavior as satire.
In Sex and the City 2, Carrie and Mr. Big watch It Happened One Night (specifically the taxi scene) in a hotel. Later in the film, in an attempt to get a taxi in Abu Dhabi, Carrie mimmicks Claudette Colbert by showing some leg to stop a taxi.
In the 2001 film Bandits, Joe Blake (Bruce Willis) erects a blanket partition between motel room beds out of respect for Kate Wheeler's (Cate Blanchett's) privacy. He remarks that he saw them do the same thing in an old movie (Clark Gable's character, Peter Warne, did this in It Happened One Night).
It Happened One Night was the first to win all five major Academy Awards (Best Picture, Director, Actor, Actress, and Screenplay), a feat that would not be matched until One Flew Over the Cuckoo's Nest (1975) and later by The Silence of the Lambs (1991).
Loretta Young also turned down the role of Elle in It Happened One Night.
Margaret Sullavan turned down the part of Ellie in It Happened One Night.
Mel Brooks' 1987 film Spaceballs parodies the wedding scene from It Happened One Night. As she walks down the aisle to wed Prince Valium, Princess Vespa (Daphne Zuniga) is told by her father, King Roland, that Lone Starr forsook the reward for the princess's return and only asked to be reimbursed for the cost of the trip.
Miriam Hopkins rejected the part of Ellie in It Happened One Night.
Robert Montgomery and Myrna Loy were offered the roles of Ellie and Peter in It Happened One Night, but each turned the script down, though Loy later noted that the final story as filmed bore little resemblance to the script that she and Montgomery and been offered for their perusal.
The 1937 Laurel and Hardy comedy Way Out West parodied the famous hitch-hiking scene from It Happened One Night, with Stan Laurel managing to stop a stage coach using the same technique.
The unpublished memoirs of animator Friz Freleng mention that It Happened One Night was one of his favorite films. It has been claimed that it helped inspire the cartoon character Bugs Bunny. Three things in the film may have coalesced to create Bugs: the personality of a minor character, Oscar Shapely, an imaginary character named "Bugs Dooley" mentioned once to frighten Shapely, and most of all, a scene in which Clark Gable eats carrots while talking quickly with his mouth full, as Bugs does.