With decisive opposition backing, Anutin on Friday easily passed the more than half of the lower house votes required to become premier, capping days of drama and a scramble for power during which he outmanoeuvred the most successful political party in Thailand's history.
Shrewd dealmaker Anutin has been a mainstay in Thai politics throughout years of turmoil, positioning his Bhumjaithai party strategically between warring elites embroiled in an intractable power struggle and guaranteeing its place in a succession of coalition governments.
His rout of rival contender Chaikasem Nitisiri was a humiliation for the ruling Pheu Thai party, the once unstoppable populist juggernaut of influential billionaire Thaksin Shinawatra, who left Thailand on Thursday for Dubai, where he spent most of his 15 years in self-imposed exile.
Anutin won 63 per cent of the votes, with double the tally of Chaikasem.
"I will work my hardest, every day, no holidays, because there is not a lot of time," Anutin told reporters as he left the chamber.
"We have to ease problems quickly."
Pheu Thai's crisis was triggered in June by Anutin's withdrawal from its alliance, which left the coalition government clinging to power with a razor-thin majority amid protests and plummeting popularity.
The hammer blow was last week's dismissal by a court of Thaksin's daughter and protege Paetongtarn Shinawatra, the sixth prime minister from or backed by the Shinawatra family to be removed by the military or judiciary.
Anutin's victory came as a result of a pact with the progressive opposition People's Party, the largest force in parliament, which he seduced with promises to hold a referendum on amending the constitution and call an election within four months.
A political veteran and son of a former cabinet minister who once ran his family's construction firm, 58-year-old Anutin is a former deputy premier, interior minister and health minister who served as Thailand's COVID-19 tsar.
As a staunch royalist, Anutin is considered a conservative, although he made a name for himself by leading a successful campaign to decriminalise cannabis in Thailand.
Anutin will lead a minority government, which the People's Party will not join, and take the helm of a country with a struggling economy.
His rise was tied to the political reckoning of powerbroker Thaksin and decline of Pheu Thai, which won five of the past six elections but has haemorrhaged support among the working classes once wooed by its populist giveaways.
Pheu Thai vowed to come back to power and deliver on its agenda, saying "we will return to finish the job for all the Thai people".
Thaksin's departure from Thailand on his private jet came after his party failed in desperate bids to dissolve the house and undermine Anutin's bloc.
A court ruling that could see Thaksin jailed is set for next week.
The tycoon made a vaunted homecoming from Dubai in 2023 to serve an eight-year sentence for abuse of power and conflicts of interest, but on his first night in prison he was transferred to a hospital on medical grounds.
His sentence was commuted to a year by the king and he was released on parole after six months' detention.
The Supreme Court will decide on Tuesday if Thaksin's hospital stint counts as time served. If not, it could send him back to jail.
Thaksin said he was in Dubai for a medical check-up and to see old friends, and would return to attend court.
