Jean Harlow
The first woman to be known as a bombshell was Jean Harlow, who was nicknamed the "blonde bombshell" for her film "Platinum Blonde" (1931). Two years later, she starred in the Metro-Goldwyn-Mayer film "Bombshell" (1933). One of the blurbs on posters was "Lovely, luscious, exotic Jean Harlow as the Blonde Bombshell of filmdom."