Preparations The
Constitutional Court of Korea has 180 days from the passage of an impeachment motion to review it. At the time of filing the impeachment motion, the court was composed of only six justices; two vacancies were subsequently filled by Choi Sang-mok after nomination by the National Assembly, leaving one vacancy. In addition, two of the six justices have tenures ending within the mandated review period in April 2025, causing additional concerns over quorum. and the PPP opposing it on the grounds that an acting president can only appoint justices only in the event of a presidential vacancy, not a suspension of duties. Yoon's impeachment became the eighth impeachment case in 2024 alone received by the courtthe highest number in a single year in South Korean history. The impeachment motion was submitted to the court on 14 December 2024, and proceedings began on 16 December, with the court calling the case a "top priority". On 16 December 2024, the court announced that trial would proceed with the original six justices then on the bench. The identity of the presiding justice, typically undisclosed, was revealed to be Justice
Jeong Hyeong-sik, a Yoon appointee, due to the gravity of the case. Former
Korea Communications Commission chair Kim Hong-il was announced as the head of Yoon's legal defense team, while National Assembly Legislation and Judiciary Committee Chair
Jung Chung-rae served as the impeachment prosecutor. On 26 December, the National Assembly approved a motion to fill the three vacancies in the Constitutional Court, with the PPP not participating in the confirmation vote. However, Acting President Han Duck-soo refused to appoint the nominees, citing the need for a bipartisan consensus. In response, the DPK filed an impeachment motion against Han that same day, On 31 December, acting president
Choi Sang-mok appointed
Chung Kyesun and
Cho Hanchang to the Constitutional Court as part of efforts to fill up the vacancies. However, he withheld the appointment of a third nominee, Ma Eun-hyuk, which the Constitutional Court ruled was unconstitutional on 27 February 2025. The first preparatory hearing for the case was held 27 December 2024, with the next hearing occurring on 3 January 2025. The National Assembly was represented in the trial by DPK lawmaker Jung Chung-rae, who is the chair of the assembly's legislation and judiciary committee. Yoon's defense team comprised Bae Bo-yoon, a former Constitutional Court scholar and spokesperson during the impeachment trial of former president Park Geun-hye; Yun Gap-geun, former head of the
Daegu High Prosecutors' Office; Bae Jin-han, a former judge and Yoon's classmate at
Seoul National University School of Law; and Kim Hong-il, former head of the
Korea Communications Commission.
Withdrawal of insurrection charge On 3 January, the National Assembly petitioners removed insurrection charges from the grounds for impeachment to focus on constitutional violations related to the martial law declaration rather than pursuing criminal charges, in order to expedite the case. Park Chan-un, a law professor at
Hanyang University, called this a logical move, as the impeachment trial is "fundamentally a 'disciplinary trial' focused on whether Yoon violated the constitution". The PPP criticized the move, claiming "the move exposed legal flaws in the impeachment motion and thus the motion should be nullified". However, the DPK defended the revision, asserting that since the impeachment trial is not a criminal proceeding, it should focus on violations of the constitution and that "the revision was necessary to expedite court proceedings". In its final verdict on Yoon's impeachment on 4 April, the Court recognized the withdrawal of the insurrection charges as valid.
Proceedings January During the 3 January hearing, Yoon's defense team defended the declaration of martial law as a "national emergency situation" and said that its brief duration "did not restrict the people's basic rights". It also said Yoon had immunity from prosecution, citing the
Supreme Court of the United States's 2024 ruling in
Trump v. United States. They also alleged media bias against Yoon but were reprimanded by Justice Cheong Hyung-sik. Meanwhile, the prosecution accused defense lawyers of distorting the nature of the trial and insulting the justices. Oral arguments for the trial began on 14 January, with another session on 16 January in the event that Yoon fails to appear. A total of five sessions would be held until 4 February, including on 21 and 23 January. On 12 January, Yoon's lawyer said that his client would not attend the 14 January hearing, citing safety concerns and the possibility of him being apprehended by investigators seeking to execute an arrest warrant against him on his way to court. On 13 January, Yoon's lawyers requested the exclusion of Justice Chung Kyesun from hearing the case, accusing her of progressive leanings and showing her "prediction" for the trials during her confirmation by the National Assembly in December 2024. It also called for the first day of the trial to be moved from 14 January, saying that the impeachment of acting president
Han Duck-soo needed to be heard first. The 14 January hearing lasted four minutes before being adjourned due to Yoon's absence. During the session, the court also dismissed the defense's request to exclude Justice Chung Kyesun from hearing the case. It also rejected Yoon's objection to the designated dates for hearings, saying the scheduling followed laws and regulations governing the Constitutional Court, not a criminal court. The impeachment team called as its witnesses Hong Jang-won, the first deputy director of the
National Intelligence Service; Cho Ji-ho, commissioner of the
National Police Agency; Kwak Jong-geun, commander of the
Republic of Korea Army Special Warfare Command; Lee Jin-woo, commander of the Capital Defense Command; and Yeo In-hyung, chief of the
Defense Counterintelligence Command. At the 16 January hearing, the court added additional hearing dates scheduled for 6, 11, and 13 February. It also called for additional witnesses, including former defense minister Kim Yong-hyun and police commissioner Cho Ji-ho, to testify. The court decided to admit surveillance footage from the National Assembly, the
National Election Commission (NEC), and the official residence of the National Assembly speaker as evidence and announced plans to fact-check Yoon's claims of electoral fraud. During the hearing, Yoon's defense team formally presented its position on the issues, while the
plaintiff outlined its arguments for impeachment. Yoon did not attend the hearing in person. His request to reschedule the hearing due to his arrest the previous day was rejected by the court. In the 21 January hearing, Yoon made his first physical appearance for his impeachment. He denied allegations that he had ordered the military to forcibly remove lawmakers from the National Assembly. Yoon stated that the soldiers deployed to the legislature were not intended to suspend the National Assembly or obstruct its efforts to lift martial law, acknowledging that such actions would have caused a crisis. On 22 January, acting president
Choi Sang-mok ordered a 24-hour police presence at the Constitutional Court and other courts nationwide following the
2025 Seoul Western District Court riot and other incidents of political tension related to Yoon's impeachment. On 23 January, Yoon appeared at the impeachment trial again, with Kim Yong-hyun present as a witness. Kim denied allegations that Yoon had ordered the military to storm the National Assembly to prevent lawmakers from convening and passing a resolution nullifying martial law. However, he admitted to recommending declaring martial law to Yoon and to writing a note to Finance Minister Choi Sang-mok, instructing the establishment of an emergency legislative body during martial law. Alongside Yoon, Kim was also accused of ordering lawmakers to be dragged out of the parliament, to which Kim responded with; "The situation was very chaotic, I thought someone might get crushed to death. So I said to pull them out for now to reduce the risk of serious harm. That’s what I meant." Yoon defended his declaration of martial law, asserting that it did not fail but acknowledging that it ended "sooner than expected".
February On 1 February, Yoon's legal team formally requested the recusal of acting chief justice Moon Hyung-bae, Justice Lee Mi-seon, and Justice Chung Kyesun from the impeachment case, citing concerns about impartiality. The team alluded to Moon's past social media interactions with DPK leader Lee Jae Myung, Justice Lee's brother, who serves as a vice chairman of a committee at the Lawyers for a Democratic Society and had supported Yoon's resignation, as well as Justice Chung's husband, who had signed a public declaration supporting Yoon's impeachment. Appearing again for the 4 February hearing, Yoon admitted to ordering soldiers to the NEC to check its systems operations, citing allegations of election fraud. He again denied accusations of him ordering the military to forcibly remove lawmakers from the National Assembly, saying that it could not have been done due to the presence of thousands of civilians outside the assembly compound. Lee Jin-woo testified that he had not received orders from Yoon or Kim Yong-hyun to obstruct the lifting of martial law by lawmakers but said he believed that the military deployment to the legislature was legitimate under the Martial Law Act. Yeo In-hyung also attended the hearing as a witness but refused to testify, citing the risk of self-incrimination in a parallel criminal investigation against him. On 8 February, police launched an investigation after reports of a planned mob attack, scheduled for 13 February, on the Constitutional Court trial emerged online. In response, more than 2,700 police personnel and 140 buses were deployed near the court on 11 February. Barricades and panels were set up to restrict access, and the court justices received armed protection. At the 11 February hearing, Yoon blamed opposition parties for his decision to declare martial law. Yoon claimed that the opposition parties had failed to give him due respect as president and described them as "malicious". Yoon cited his addresses to the National Assembly, during which he said opposition lawmakers refused to attend or shake hands and turned away from him. Former interior minister Lee Sang-min also testified before the court and denied that Yoon had ordered him to cut off electricity and water supplies to left-leaning media outlets critical of Yoon, specifically the
Hankyoreh, the
Kyunghyang Shinmun,
MBC and
JTBC, as well as the opinion polling agency Flower Research during martial law. At 13 February hearing, which Yoon attended, former
NIS first deputy director Hong Jang-won, who previously testified to compiling a list of politicians as instructed by Yoon to "clean them all up" during martial law, revealed that he had been contacted through text messages by first lady
Kim Keon Hee on the night of martial law, but could not recall the exact details. His statement was disputed by NIS director Cho Tae-yong, who cited multiple discrepancies and accused Hong of links with opposition politicians. Col. Cho Seong-hyun, commander of the 1st Security Group at the Capital Defense Command and the only witness directly requested by the court, also testified that his commanding officer Lee Jin-woo ordered him to support special forces soldiers at the National Assembly as they dragged lawmakers out of the building. The Constitutional Court also set an additional impeachment hearing to be held on 18 February. On 14 February, it also set an additional hearing scheduled on 20 February and ordered Han Duck-soo to testify as a witness. Yoon arrived at the Constitutional Court for the 18 February hearing but left shortly before it began after it was determined following a meeting with his lawyers that his attendance was unnecessary. The hearing proceeded with the prosecution and defense summarizing their arguments. The court also rejected an appeal by Yoon's lawyers to postpone the 20 February hearing due to a scheduling conflict with the first preliminary hearing of Yoon's separate criminal trial on insurrection charges. However, the court agreed to push back the opening of the hearing by an hour. The court also issued a
subpoena for Cho Ji-ho, who refused to testify as a witness for the third time, citing health issues. Yoon arrived at the Constitutional Court for the 20 February hearing but left shortly after his lawyers determined that it would be inappropriate for him to watch Han Duck-soo testify, reentering once Han had finished. Han said that members of Yoon's cabinet were concerned about his plans to declare martial law and tried to dissuade him from doing so, while denying claims from Kim Yong-hyun that some members were in support of the plan. He also said that the martial law declaration did not follow constitutional and legal procedures and questioned whether Yoon's cabinet meeting on 3 December was a proper one. Cho Ji-ho, who finally appeared at the trial, refused to answer most questions presented at him, citing a related criminal trial. Later, the court set the final impeachment hearing on 25 February. At the 25 February hearing, Yoon said he was "sorry and thankful to the people". He also pledged to push for political reforms and a constitutional revision to change the current presidential system if his impeachment is overturned, adding that the fulfillment of such pledges might lead to him leaving office before the end of his term. At the same time, he continued to deny the accusations of insurrection against him and accusations that of him interfering with the National Assembly's affairs. He also continued to defend martial law, saying that it was intended to appeal to the public about the "imperial opposition party" and accused the latter of exploiting experiences from previous martial law declarations to "incite public fear". Lee Kwang-beom, one of the prosecution lawyers, compared Yoon to previous South Korean presidents including
Park Chung Hee and
Chun Doo-hwan, adding that Yoon's declaration of martial law was "dictatorship". The trial ended with a total of 11 hearings held over 73 days and 16 people testifying as witnesses.
March On 12 March, the government imposed a
no-fly zone within a radius of 1 nautical mile from the Constitutional Court that would last until 19 March. The National Police Agency also said it would declare its highest-level security protocol on the day the court issues its verdict on Yoon's impeachment. On 16 March, PPP floor leader
Kweon Seong-dong said the party would respect the Constitutional Court's verdict on Yoon's impeachment regardless of its outcome.
April On 1 April, the Constitutional Court announced that it would issue its verdict regarding Yoon's impeachment at 11:00 KST on 4 April. In response, multiple venues and events scheduled in Seoul on the said date were closed, cancelled or postponed. Police also imposed a "vacuum zone" and sealed off the area within a 150-meter radius around the Constitutional Court with police buses. About 96,370 people applied for 20 available spectator seats to attend the verdict at the court, making it the highest number of applicants to try and attend an impeachment proceeding in South Korea. Yoon declined to attend the reading of the court's verdict. On the day before the verdict (3 April), 14,000 police officers were deployed, with Level 2 emergency response status being issued. City buses were diverted, and additional police were sent to major political sites. On the day of the ruling, the emergency status was raised to level 1, allowing for 100% of the police to be deployed.
Verdict On 4 April, the Constitutional Court upheld the impeachment in a unanimous 8–0 decision, which formally removed Yoon from office, effective at 11:22
KST. In the decision read out by acting Chief Justice of the Constitutional Court
Moon Hyung-bae, the court declared that Yoon did not follow procedures for declaring martial law. He further stated that Yoon "went against those he was supposed to protect" and "damaged people's political rights." The court also acknowledged "the resistance of citizens" in helping prevent the full implementation of martial law, and said that Yoon's conflict with the National Assembly was "a political issue that must be resolved within the bounds of democracy", adding that the legislature's use of its powers "did not, in itself, create a severe crisis situation at the time justifying the declaration of martial law" while saying that the chamber should have respected minority opinions and made efforts towards compromise. It also ruled that verbal statements made by key suspects to prosecutors regarding plans of arrests by Yoon were admissible. The verdict came 111 days after his impeachment by the National Assembly, the longest of any South Korean presidential impeachment verdict. Yoon's removal from office makes him the shortest-serving president under the democratic
history of South Korea. The court issued a 114-page decision citing serious violations of the constitution and a breach of
public trust. The ruling outlined five major constitutional violations committed during the imposition of martial law on 3–4 December: •
Failure to meet substantive requirements for declaring martial law: The court found that political gridlock and allegations of election fraud did not constitute grounds for martial law. Such issues, it stated, should be addressed through political, institutional, and judicial means. Yoon's justification of the declaration as a "warning" or "appeal to the public" was not recognized as legitimate under the Martial Law Act. •
Failure to meet procedural requirements: Yoon did not inform the martial law commander or other officials of the details of the declaration, did not hold cabinet deliberations, and failed to obtain required signatures from the prime minister and relevant ministers. He also did not publicly announce the scope, timing, or command structure of martial law, nor did he notify the National Assembly without delay. •
Interference with the authority of the National Assembly: Yoon deployed military and police forces to prevent lawmakers from entering the National Assembly, obstructing their rights to deliberate, vote, and exercise immunity from arrest. •
Violation of judicial independence: The court found that Yoon was involved in tracking and planning the arrest of former and current members of the judiciary, including former chief justice
Kim Myeong-su and other retired justices, thereby exerting pressure on the judiciary. •
Infringement of political freedoms and constitutional order: The court ruled that Yoon ordered the tracking of political opponents through the National Intelligence Service (NIS), used military forces to obstruct political institutions, and issued martial law decrees that violated constitutional protections, including the rights to political activity, assembly, occupation, and the separation of powers. Additional violations cited included unauthorized searches and seizures at the National Election Commission (NEC), and orders to inspect NEC computer systems, confiscate staff devices, and conduct surveillance without a warrant. These actions, the court stated, infringed upon the NEC's independence. As a result of the ruling, Yoon lost presidential immunity and became subject to criminal prosecution. His trial on charges of insurrection began on 14 April. If found guilty, Yoon faces the
death penalty or
life imprisonment, although there has been a moratorium on executions in South Korea since 1997. ==Popular reactions==