It's possible that:
* You're misremembering the film or the dancer's appearance. Perhaps you're thinking of another film or show, or the dancer wasn't a prominent character.
* The dancer was not credited in the film. Many dancers in older films, particularly those in ensemble scenes, weren't credited.
To clarify your question, it would be helpful if you could provide:
* More details about the dancer: What scenes were they in? What was their role? Anything specific you remember about them?
* The specific scene you're thinking of: Perhaps a scene with a beach party or a particular song playing.
With more information, it might be possible to identify the dancer you're looking for.