She will lead the government to elections due within months.
Gillard stood unopposed at a vote of the Labor Party's 112 lawmakers at a meeting today, hours after a revolt against Rudd, AP reported.

Since she is leader of the majority party in Parliament, Gillard's swearing in as Prime Minister is a formality.

Rudd won a landslide election victory less than three years ago but suffered a recent plunge in opinion polls, reports added.

Sri Lanka had its first female Prime Minister in 1960. Former Prime Minister Sirimavo Bandaranaike was also the world's first female Prime Minister.