'Congratulations to Thailand's first female prime minister,' he said.
Authorities were still counting votes, but Yingluck said her Pheu Thai party already appeared to have garnered a majority of votes based on the existing tally.
'I would like to take this opportunity to thank all the people and thank you for every vote you have given to us,' Yingluck told reporters at her campaign headquarters Sunday night.
Yingluck's brother, Thaksin Shinawatra, was ousted as prime minister in a 2006 military coup.
With about 47 million eligible voters in Thailand, the balloting was held to decide Thailand's first general election since 2007, an election that many hope will bring an end to years of unrest between two political factions that climaxed last year with protests that turned deadly.
