
Leslie Jean Mann was born in San Francisco, California. She was raised in Newport Beach, California by her mother, Janet Ann Ayres. At the age of seventeen, she launched her career, appearing in various TV commercials.
Her screen break came when she was cast as Nurse Mary in the short-lived Birdland (1994). Further TV and film roles followed, including O Pentelho (1996), where she met her husband, Judd Apatow, who was a producer on the film. The story goes that after Mann left her audition for the role, Apatow turned to his colleagues and said "there goes the future Mrs. Apatow".
Further successes followed for Mann in such projects as George, o Rei da Floresta (1997) and O Virgem de 40 Anos (2005). She also appeared alongside her daughters - Maude Apatow and Iris Apatow - in Ligeiramente Grávidos (2007), Tá Rindo do Que? (2009) and Bem-vindo aos 40 (2012).