Lydia Bilbrook, sometimes credited as "Bilbrooke", was an English actress whose career spanned four decades, first as a stage performer in the West End, and later in films. She is best known to today's audiences as "Lady Ada Epping" opposite comedian Leon Errol in the Mexican Spitfire movie comedies of the 1940s.

Mexican Spitfire refers to a series of eight comedy films released by RKO Pictures between 1940 and 1943 starring Lupe Vélez and Leon Errol. The movies featured the character of Carmelita Fuentes, a sympathetic but temperamental Mexican singer who leaves her career and native country to meet and marry Dennis Lindsay, an elegant and handsome American advertising executive.