Mickey Rooney was supposed to star in this movie, but he ended up being drafted into the war, so Robert Walker was cast instead.
Despite his portrayal of the cheerful and optimistic Jimmy Dobson in this film, Robert Walker was enduring severe bouts of stress and depression. During production he was embroiled in divorce proceedings with his estranged wife, Jennifer Jones, who had left Walker and their children for producer David O. Selznick. The situation left a lasting impression on Walker, who never quite recovered, and battled depression and alcoholism for the rest of his short life. The cast and crew of this film marveled at Walker's ability to portray the chipper Jimmy while he was experiencing such sadness and hardships in real life.
MGM saved money by re-using the hotel sets from Weekend at the Waldorf (1945). After that film wrapped production, Her Highness and the Bellboy (1945) moved in.
Hedy Lamarr insisted on top billing. Her relative star power had waned, and several of the film's up-and-coming young stars were likely more popular with audiences at the time. After a heated fight with the star, the studio acquiesced and Lamarr was billed first. However, her inflexibility on the matter likely contributed to the studio's unwillingness to renew her contract and, as result, this was her last motion picture for MGM. After this she freelanced.
Hedy Lamarr was pregnant with her daughter while making this film. Because of this, she mostly appears in close-ups featuring her face, and scenes had to be filmed carefully in order to conceal her body.