A pretty and promising Australian-born actress in Hollywood films from the early 1930s, pinch-cheeked Mary Maguire was born Helene Teresa ("Peggy") Maguire in Melbourne, one of five children born to footfall player and boxer turned hotelier Michael "Mick" Maguire. One of her sisters became actress Joan Shannon.A student at the Academy of Mary Immaculate in Fitzroy, the fresh-faced actress made her film bow unbilled in the film Diggers in Blighty (1933). Billed as "Peggy Maguire" in her second film Heritage (1935) directed by Charles Chauvel, who discovered her, she received good reviews for this and earned another fine role opposite Charles Farrell in The Flying Doctor (1936) in which she changed her stage moniker to "Mary Maguire".In the United States from August of 1936, Warner Bros. signed her to a seven-year contract and cast her in That Man's Here Again (1937) co-starring Tom Brown. Other roles came her way with Confession (1937) and L'île du diable (1937) and Sergeant Murphy (1938). Warner Bros. released her from her contract when she refused a role in Mystery House (1938).Fox signed her up briefly in 1938 and cast her as the lead in M. Moto dans les bas-fonds (1938), the Gracie Fields musical Keep Smiling (1938) and in Le triomphe de l'amour (1939). From there she signed up with British Picture Corp. and starred in Black Eyes (1939) with Otto Kruger and An Englishman's Home (1940) with Edmund Gwenn.Marriage and the birth of a child joyously interrupted her career, but when the child died suddenly in infancy, the devastated Mary returned to work and was cast in the British film This Was Paris (1942) starring Ann Dvorak and Ben Lyon, but no other future films came her way.A second marriage to Philip Henry Legarra in 1945 prompted a sudden move back to the States where he worked as an engineer. An attempt to resurrect her film career failed. The marriage lasted until his death in 1971 and Mary passed away three years later, interred alongside her husband at Forest Lawn in Glendale, California.