María de Lourdes Villiers "Mia" Farrow (born February 9, 1945) is an American actress, activist, and former fashion model. Farrow has appeared in more than 50 films and won numerous awards, including a Golden Globe Award and three BAFTA Award nominations. Farrow is also known for her extensive work as a UNICEF Goodwill Ambassador, which includes humanitarian activities in Darfur, Chad, and the Central African Republic. In 2008, Time magazine named her one of the most influential people in the world.

The eldest daughter of Australian director John Farrow and Irish actress Maureen O'Sullivan, Farrow had a strict Catholic upbringing in Beverly Hills, California. After working as a fashion model during her teenage years, she first gained notice for her role as Allison MacKenzie in the television soap opera Peyton Place (1964–1966). Her credited feature film debut in Guns at Batasi (1964) earned her a Golden Globe Award for New Star of the Year, and she gained further recognition for her subsequent two-year marriage to Frank Sinatra, whom she married at age 21. Farrow's portrayal of Rosemary Woodhouse in the horror film Rosemary's Baby (1968) earned her a nomination for a BAFTA Award and a Golden Globe Award for Best Actress. She received a third Golden Globe nomination for her role in John and Mary (1969).