Prime Minister of Thailand sixteen out of twenty-nine, including the incumbent General Prayut Chan-o-cha. Military dominance began with the country's second Prime Minister, Phot Phahonyothin, who ousted his civilian predecessor in a coup in 1933. The longest serving Prime Minister was Field Marshal Plaek Pibulsonggram at 14 years, 11 months and 18 days. The shortest was Tawee Boonyaket at just 18 days. Nine were removed by coups d'état, three were disqualified by court order, and eleven resigned from office. The youngest ever to occupy office was M.R. Seni Pramoj at 40 years old. Thailand received its first female prime minister, Yingluck Shinawatra, in 2011.
Prime minister-designate leader of the largest opposition party therefore could still become prime minister-designate perhaps several weeks after the general election. The term prime minister-elect is sometimes used as a synonym, but in most circumstances it is technically incorrect: a prime minister is usually appointed by the head of state, and not elected to office by the entire nation, as is the case with some presidential polls. However, it has nonetheless seen common use in the media. Terms such as incoming prime minister and prime minister-in-waiting are also sometimes used, although the latter term is also sometimes used prior to an election