South Korea's Constitutional Court removed President Park Geun-hye from office on Friday over a graft scandal involving the country's conglomerates at a time of rising tensions with North Korea and China.
The ruling sparked protests from hundreds of her supporters, two of whom were killed in clashes with police outside the court.
Park becomes South Korea's first democratically elected leader to be forced from office, capping months of paralysis and turmoil over a corruption scandal that also landed the head of the Samsung conglomerate in jail.
A snap presidential election will be held within 60 days.
Park will not leave the presidential Blue House residence on Friday, her spokesman said following the verdict. Park was stripped of her powers after parliament voted to impeach her but has remained in the president's official compound, the Blue House.
The court's acting chief judge, Lee Jung-mi, said Park had violated the constitution and law "throughout her term", and despite the objections of parliament and the media, she had concealed the truth and cracked down on critics.
"The removal of the claimee from office is overwhelmingly to the benefit of the protection of the constitution... We remove President Park Geun-hye from office," Lee told the hearing.
Park denied any wrongdoing.
The ruling to uphold parliament's Dec. 9 vote to impeach her over the scandal marks a dramatic fall from grace of South Korea's first woman president and daughter of Cold War military dictator Park Chung-hee. Both of her parents were assassinated.
She did not appear in court and a spokesman said she would not be making any comment on Friday.
Park, 65, no longer has immunity as president, and could now face criminal charges over bribery, extortion and abuse of power in connection with allegations of conspiring with her friend, Choi Soon-sil.