Vélez began her career as a performer in Mexican vaudeville in the early 1920s. After moving to the United States, she made her first film appearance in a short film in 1927. By the end of the decade, in the last years of the American Silent cinema, she had progressed to leading roles in numerous films like El Gaucho (1927), Lady of the Pavements (1928) and Wolf Song (1929), among others. She was one of the first successful Latin American actresses in the United States. During the 1930s, her well known explosive screen persona was exploited in a series of successful films like Hot Pepper (1933), Strictly Dynamite (1934) and Hollywood Party (1934). In the 1940s, Vélez's popularity peaked after appearing in the Mexican Spitfire films, a series created to capitalize on Vélez well documented fiery personality.