- Awesome, Dear Boy: Rosemary Clooney claimed that she did the film purely to perform with Bing Crosby.
- Dawson Casting: 32-year-old Vera-Ellen as "Little Judy". (By contrast, older sister Betty was played by 25-year-old Rosemary Clooney.) Bing Crosby was 51 at the time the movie was filmed, although Bob Wallace is supposed to be at least a few years younger than that.
- Non-Singing Voice: Vera-Ellen's singing voice was dubbed. Numerous sources mistakenly assume Rosemary Clooney sang Vera-Ellen' s part in "Sisters" thus duet-ing with herself, but Trudy Stevens (who was Trudy Stabile at the time) was Vera-Ellen's voice double in all of her songs, namely "Sisters", "Snow" and the "White Christmas" finale. Vera's own singing voice is heard ever very briefly singing in the "arrival in Pine Tree" scene at the railroad station where the quartet reprises - live - the opening lines of "Snow".
- Throw It In!:
- Bob's speech about the effects of sandwiches on dreams was nearly completely improvised by Crosby.
- Bob and Phil's performing the girls' number was originally just Crosby and Kaye having some fun, but it turned out so well the director decided to work it in. Watch for Crosby trying valiantly not to corpse in the middle of the act, particularly when Kaye smacks him in the face with a feathered fan.
- Uncredited Role: Bob Fosse was the uncredited choreographer for the movie.
- Unintentional Period Piece: The film is set in an America where nightclubs are places where people dress up, dance formally, and hear live entertainers perform what are today called standards. Those entertainers gain stardom by appearing on regular radio shows and starring in Broadway revues (variety shows). They travel from Florida to Vermont, and thence to New York, by train; once in New York, they appear on prime-time, live-broadcast, black-and-white TV, and at home the whole family gathers around to watch. And the whole plot is centered around men doing things "for an old pal from the Army" the bond created amongst a generation by World War II.
- What Could Have Been: Fred Astaire turned down the role of Phil Davies.
Trivia / White Christmas