Age: 67
Occupation: Prime Minister of Iceland
Previous TIME 100 Appearances: 0
After Iceland's economy collapsed in October 2008, Sigurdardottir rode a wave of discontent all the way to the premiership. A former flight attendant and the world's first openly gay head of state, she must rebuild the nation's economy while boosting confidence abroad. But vital foreign aid remains on hold until Sigurdardottir finds a way to repay $5 billion in losses to Britain and the Netherlands. Both governments bailed out their citizens who had invested in Icesave, the now defunct Reykjavik-based online bank. Sigurdardottir's reputation — and the nation's credit rating — depends on the outcome.