Penny Singleton's paternal lineage was rooted in her Irish Philadelphian father, Benny McNulty, a newspaperman of great renown. Interestingly, her father was related to Jim Farley, the campaign manager and later U.S. Postmaster General under President Roosevelt. As a child, Penny's love for music was evident, as she would often sing songs at a silent movie theater. This talent led her to join a touring vaudeville act called "The Kiddie Kabaret" after completing the sixth grade. Under the stage name Penny McNulty, she sang, danced, and entertained audiences alongside renowned performers such as Milton Berle and Gene Raymond.
Penny's early foray into the world of spoken roles came when she landed a part in Jack Benny's Broadway show, "Great Temptations". Later, she made the transition to Hollywood, where she took on a new surname after marrying dentist Lawrence Singleton. Her first name, Penny, was inspired by her habit of saving large amounts of penny coins. In her early film career, Penny played a tough nightclub dancer in the 1936 movie "After the Thin Man" and later acted, sang, and danced in the 1938 film "Swing Your Lady", a movie that Humphrey Bogart himself considered one of his worst. Despite being a natural brunette, Penny bleached her hair blonde after landing the iconic role of Blondie in the long-running series, a character that would become synonymous with her name.
