The Christmas song "Have Yourself a Merry Little Christmas" was written for this film.

In the film, when Margaret O'Brien is sad because she doesn't want to move, she knocks down snowmen and cries hysterically. It is rumored that in real life Margaret was told that her dog died when it really hadn't, just so she would cry. Apparently Margaret O'Brien denies this, claiming this story is not true. She explains that though she didn't feel it was easy to cry, she was able to muster it after being told that June Allyson - her MGM rival in sobbing - could cry on cue.

The address - 5135 Kensington Ave. - sung about by Judy Garland in "The Boy Next Door" was a real St. Louis address located near the World's Fair grounds. The house, torn down just a few years ago, was a row house, though, not the sprawling Victorian mansion shown in the film.