Socialist Michelle Bachelet, who was Chile's president from 2006 to 2010, cruised to victory in Sunday's presidential runoff.
With more than 93% of votes counted, she won 62.3% of votes, election officials said. Evelyn Matthei of the conservative Independent Democratic Union party garnered 37.7% of votes.
Bachelet will take over from Sebastian Pinera in March.
She was the first female president of Chile and left office with high approval ratings.
In 2010, Bachelet was tapped to head U.N. Women, a United Nations agency created to promote gender equality around the world.
Chilean voters first cast ballots in last month, but no candidate secured enough votes then to declare victory.
The South American country's constitution requires a presidential candidate to garner more than 50% of votes to win. Presidents are prohibited from seeking immediate re-election.