The 64-year-old monk set himself alight on Saturday night in central Seoul where hundreds of thousands of people had gathered to rally for the 11th week to demand Park’s immediate removal.
He suffered severe burns across his face and body and died Monday night, according to Seoul National University Hospital where he was being treated.
The monk, who has been identified as Venerable Jung-Won, left a note urging authorities to arrest the scandal-hit president for committing “treason” and criticising policies of her administration.
He also slammed Park as a “traitor” for forging a deal with Japan to settle compensation for women forced into sexual slavery for Japanese troops during World War II, according to Yonhap news agency.
“Ven. Jung-Won… sacrificed his life to convey people’s sentiment including… the demand for President Park Geun-Hye to resign. We hope that no lives will be lost like this and the whole country will be stabilised soon,” the social justice committee of the Jogye Order of Korean Buddhism said in a statement.
Self-immolation is not unheard of as a mean of protest in the South, where many pro-democracy activists set themselves on fire in the 1970s and 80s during demonstrations against military rule.
Park was impeached by parliament last month over an influence-peddling scandal involving a secret confidante that sparked a storm of public fury and nationwide protests.
Park is accused of colluding with a longtime friend, Choi Soon-Il, to strong-arm donations worth tens of millions of dollars from top firms which were then funnelled to dubious foundations which Choi used as her personal ATMs.
The president is also accused of letting Choi — currently on trial — meddle in a wide range of state affairs including nomination of top officials.
The Constitutional Court is reviewing the validity of the impeachment bill. Both Park and Choi have denied any wrongdoing.