Who was the first woman prime minister in the world?

Sirima Ratwatte Dias Bandaranaike, commonly known as Sirimavo Bandaranaike, was a Sri Lankan stateswoman. She became the world's first non-hereditary female head of government in modern history, when she was elected Prime Minister of Sri Lanka in 1960. She served three terms: 1960–1965, 1970–1977 and 1994–2000.