Mannix was born Camille Bernice Froomess on February 19, 1906^[1] in New York City. Her father, Charles, was a French immigrant, and her mother, Elizabeth, was a French Canadian Roman Catholic. The large family would ultimately include 11 children: seven boys and four girls. The children were raised in their mother's faith. Mannix's father was a department store window decorator in Rochester, New York, and her mother was a homemaker.^[2]

For a time, Mannix was a Ziegfeld Follies showgirl and appeared in the Metro-Goldwyn-Mayer biography of Florenz Ziegfeld's life, The Great Ziegfeld (1936).^{[citation needed]}

Toni Lanier, the Ziegfeld dancer and actress^[1] met MGM's general manager Eddie Mannix in the 1930s. She later lived with him as his mistress, and then as his wife, until he died in 1963. Shortly after her marriage to Mannix in 1951 and shortly before the launch of George Reeves to stardom in the successful television series Adventures of Superman, Mannix met and began an extramarital affair with Reeves, with the permission of her husband, according to Reeves' co-stars Noel Neill and Jack Larson.^[3]

Reeves ended the affair in 1958 after meeting and starting a relationship with "B-girl" Leonore Lemmon in New York^[1] while he was traveling on business. His death by gunshot wound to the head five months later was officially ruled a suicide, although questions have been raised about the circumstances under which he died.^[4] Mannix was devastated by Reeves' death and remained dedicated to him, reportedly building a shrine to him in her house.^{[citation needed]}

• Toni Mannix at IMDb
• Toni Mannix at Find a Grave