A former army chief who seized power in 2014, Mr Prayut has ruled Thailand for nearly a decade and is the top prime minister candidate of conservative United Thai Nation Party.
He has a head start in the race, as he is favoured to win the backing of many of the 250 senators, whose votes will be key to picking the next leader.
As junta leader, Mr Prayut cracked down on dissidents and claimed he would restore peace and order after his coup stopped months of street protests against then Premier Yingluck Shinawatra, sister of former prime minister Thaksin Shinawatra – whose term was also ended by a military takeover.
Mr Prayut oversaw the royal succession of King Maha Vajiralongkorn at a critical juncture in Thailand’s history after the passing of much-beloved King Bhumibol Adulyadej, who reigned for 70 years.
Mr Prayut was chosen to stay on as prime minister after the 2019 election, when conservative Palang Pracharath Party cobbled together a coalition of 18 parties to keep him in power.
He is known to have a temper and there were instances he displayed it publicly, including in the presence of journalists.
At the same time, he has composed several ballads about patriotism and unity, which portray him as an honest and misunderstood leader who will steer Thailand through rough waters.
