What is the name of the American dance king who danced Sleepless Tonight?

The man who danced Sleepless Tonight is the American dance king Fred Astaire.

"Sleepless Tonight" is a segment from the American movie "Golden Dreams".

Golden Dreams is a romantic comedy film directed by Sidney Langfield, with Fred Astaire and Rita Hayworth. The film tells the story of a married dance theater executive who takes a fancy to the troupe's goddess.