The vote capped more than a week of intense political drama in the democratic South following Yoon's failed attempt to impose martial law on Dec. 3.

Hundreds of thousands of people took to the streets of the capital Seoul in rival rallies for and against Yoon on Saturday.

In a televised address following the parliamentary vote, Yoon said he would "step aside" but did not apologize for his actions.

Out of 300 lawmakers, 204 voted to impeach the president on allegations of insurrection while 85 voted against. Three abstained, with eight votes nullified.

Yoon has been suspended from office while South Korea's Constitutional Court deliberates on the vote, with Prime Minister Han Duck-soo taking over as interim president.

The court has 180 days to rule on Yoon's future and Chief Justice Moon Hyung-bae vowed to hold "a swift and fair trial".

If the court backs his removal, Yoon will become the second president in South Korean history to be successfully impeached.

Two hundred votes were needed for the impeachment to pass, and opposition lawmakers needed to convince at least eight parliamentarians from Yoon's conservative People Power Party (PPP) to switch sides.

"Today's impeachment is the great victory of the people," opposition Democratic Party floor leader Park Chan-dae said following the vote.

PPP lawmaker Kim Sang-wook told broadcaster JTBC that Yoon had "completely betrayed the values of conservatism".

"That is why we, as ruling party lawmakers, have decided to remove him ourselves," he said.

Han said in an address to the nation that he "deeply acknowledges the heavy responsibility for the current situation" and "sincerely apologizes to the people".

"What is most important right now is that there must not be even the slightest gap in the administration of state affairs," said Han, who convened a National Security Council meeting late Saturday evening.

'We, the people'

A Seoul police official told AFP at least 200,000 people had massed outside parliament in support of removing the president.

Choi Jung-ha, 52, danced in the street after the vote. 

"Isn't it amazing that we, the people, have pulled this off together?" she told AFP.  "I am 100 percent certain the Constitutional Court will side with the impeachment."

On the other side of Seoul near Gwanghwamun square, police estimated 30,000 had rallied in support of Yoon, blasting patriotic songs and waving South Korean and American flags.

"Yoon had no choice but to declare martial law. I approve of every decision he has made as president," supporter Choi Hee-sun, 62, told AFP before the vote.

South Korean National Assembly Speaker Woo Won-shik (center) bangs the gavel to initiate the plenary session for the impeachment vote of President Yoon Suk Yeol at the National Assembly in Seoul on Dec. 14, 2024. South Korean lawmakers on Dec. 14 voted to remove President Yoon Suk Yeol from office for his failed attempt to impose martial law last week. (AFP/Woohae Cho/Pool)

The Democratic Party said ahead of the vote that impeachment was the "only way" to "safeguard the Constitution, the rule of law, democracy and South Korea's future".

"We can no longer endure Yoon's madness," spokeswoman Hwang Jung-a said.

At the rally supporting impeachment, volunteers gave out free hand warmers to fight the subzero temperatures, as well as coffee and food.

K-pop singer Yuri of the band Girls' Generation, whose song "Into the New World" has become a protest anthem, said she had prepaid for food for fans attending the demonstration.

"Stay safe and take care of your health!" she said on a superfan chat platform.

One protester said she had rented a bus so parents at the rally would have a place to change diapers and feed their babies.

Another said they had initially planned to spend their Saturday hiking. "But I came here instead to support my fellow citizens," Kim Deuk-yun, 58, told AFP.

Yoon's future will now be determined by the court, which has previously blocked an impeachment.

In 2004, then-president Roh Moo-hyun was removed by parliament for alleged election law violations and incompetence, but the Constitutional Court later reinstated him.

Yoon remained unapologetic and defiant as the fallout from his disastrous martial law declaration deepened and an investigation into his inner circle has widened.

His approval rating, never very high, plummeted to 11 percent, according to a Gallup Korea poll released Friday. The same poll showed that 75 percent supported his impeachment.

Top United States diplomat Antony Blinken called the impeachment a sign of South Korea's "democratic resilience," saying Washington was "ready to work with President Han as he assumes office."

"We strongly support the Korean people. We strongly support the ironclad alliance" between the US and South Korea, Blinken told reporters on a trip to Jordan.

An EU spokesperson meanwhile called for a "swift and orderly resolution" to South Korea's political crisis in line with its constitution.