The Bhumjaithai Party's Anutin led from the start in what turned out to be a rout of his biggest rival, Natthaphong Ruengpanyawut, leader of the progressive People's Party, the surprise runner-up last month in an election it had been widely expected to win.
Anutin becomes the first Thai premier to be voted back to office in two decades, underlining the upheaval that has dogged Southeast Asia's second-largest economy.
In a stunning turnaround in fortunes for a party that had struggled to make its mark in Thai politics, Bhumjaithai scored a decisive election victory over its reformist rival after capitalising on a wave of nationalism arising out of military conflicts with Cambodia last year.
Much of Anutin's success comes from his opportunism last year in seizing on the decline of the once dominant Pheu Thai party, first by abandoning its coalition government then manoeuvring swiftly to form his own after a court sacked a second prime minister in the space of just over a year.
Bhumjaithai's coalition pact with the politically bruised Pheu Thai and a motley crew of small parties stood firm in Thursday's vote, with Anutin comfortably reaching the 251 votes needed to win re-election.
His alliance is expected to control 292 of the current 499 seats in parliament.
In the lead-up to the vote, Anutin, 59, pledged to get to work immediately on forming a cabinet and solving Thailand's problems.
"Your voices are equally heard," he told rival MPs.
"I'm ready to accept suggestions so I can carry out my duty as head of government. We all have the same goals - the wellbeing of the people."
Anutin, a staunch royalist, has been a mainstay in Thai politics, weathering two decades of upheaval by positioning Bhumjaithai strategically between warring elites entangled in an intractable power struggle, which guaranteed its place in a succession of coalition governments.
Anutin's election victory and approval by parliament gives him his first clear mandate to lead in a country with a long-stuttering economy shackled by massive household debt and facing headwinds from trade uncertainty and the fallout of the US-Israeli war on Iran.
Anutin's survival instincts and ability to straddle political divides could prove his biggest asset, some analysts say, with Bhumjaithai having been spared the wrath of Thailand's powerful military and judiciary, the engineers of the downfall of multiple governments and parties.
