Judith "Judy" B. Landon (1928 - ) was an actress and dancer who primarily played uncredited bit parts in films in the early 1950s, particularly a background dancer in movie musicals. Particularly notable roles include Eras in the film Prehistoric Women and an uncredited but recognizable performance as the silent screen vamp Olga Mara in Singin' in the Rain. All of her film roles except for Prehistoric Women were in musical films, and all of her musical film roles, except in Gentlemen Prefer Blondes, were in films distributed by MGM. Prior to her film career she had danced with various theatrical groups  including the Los Angeles Civic Light Opera. After her film career ended she made a few television appearances, including as a ballet teacher on an episode of The Brady Bunch, and an episode of her then-husband Brian Keith's show Family Affair.
- The Brady Bunch (1973...1 Episode) as Miss Clariette
- Family Affair (1967...1 Episode) as Margo Dunbar
- Singin' in the Rain (1952) (uncredited) as Olga Mara
- Prehistoric Women (1950) as Eras