On 4 April, the Constitutional Court upheld President Yoon Suk-Yeol’s impeachment over his martial law declaration in December 2024. All eight judges voted unanimously to remove him from office for violating the constitution. The Court’s decision takes effect immediately and will prompt an election within 60 days to replace him. Political experts suggest that the Court’s ruling, which featured support of conservative justices, reflects a significant recognition of the country’s rule of law and resilience against democratic threats. 

Sources: International IDEA, The Korea Herald (1), The Korea Herald (2), The New York Times, Channel News Asia

On 26 March, a South Korean appeals court overturned a 2024 lower court ruling that had found main opposition party leader Lee Jae-myung guilty of violating election laws. The charges against Lee originated from allegedly false claims he made during a 2021 parliamentary audit as governor, regarding a land development project that took place while he served as mayor of Seongnam. If the original ruling had been upheld, Lee would have lost his parliamentary seat, been sentenced to two years in prison and been barred from seeking elected office for ten years. The case has a high level of political relevance in light of the upcoming presidential election. Lee stated that the case was politically motivated and that the ruling vindicated him. Prosecutors said they plan to appeal the decision to the Supreme Court. While the election law violation case was considered Lee’s most significant legal challenge, he still faces several other trials on charges including bribery and other crimes related to a USD 1 billion property development scandal.

Update: On 1 May, the Supreme Court unexpectedly overturned the appeal court’s ruling that cleared Lee Jae-myung of election law violations. However, this did not prevent him from participating and winning the recent snap election, as the Seoul High Court sentencing process takes time, and he can appeal to the Supreme Court again.

Sources: The Korea Times (1), The Korean Herald, Al Jazeera, Chosun Daily, CSIS, The Korea Herald (2), The Diplomat

On 27 February, the Constitutional Court ruled that acting President Choi Sang-mok’s decision to withhold the appointment of a ninth justice to fill a vacancy on the Court’s bench in December was unconstitutional. While Choi said he would respect the Court’s decision, experts suggest that a ruling by a full-nine-member bench on President Yoon Suk Yeoul’s impeachment trial is unlikely, given that the current eight judges have already concluded the final hearing. The Court's decision does not specify when Choi must appoint the justice. However, legal experts have advised Choi to move forward so the Court can address various needs promptly. The decision enables the Court to carry out its functions independently and effectively.

Sources: The Korea Herald, International IDEA, The Korea Times

On 3 December, President Yoon Suk-yeol declared emergency martial law in the country for the first time in 45 years. It remains unclear why martial law was imposed as South Korea’s constitution only permits its use during “wartime, war-like situations or other comparable national emergency states.” Yoon defended his action as a “legitimate act of governance” and accused opposition lawmakers of pro-North Korean anti-state activities. Political analysts, however, note that these claims appear baseless and his action was in response to the opposition-controlled parliament’s failure to pass his budgets. However, Yoon revoked the order hours later after lawmakers, amid mass protests, voted down the decree. On 14 December, the National Assembly voted to impeach Yoon, arguing he had acted unconstitutionally. This is the second time a president has faced impeachment proceedings in less than a decade. Yoon remains suspended until the Constitutional Court rules to either reinstate him or remove him from office permanently. Prime Minister Han Duck-Soo, who stepped in to serve as acting president, was also impeached on 27 December, accused of participating in Yoon’s martial law imposition. Finance Minister Choi Sang-mok is currently the acting president.

Update: On 24 March 2025, the Constitutional Court overturned the impeachment of Prime Minister Han Duck-soo, reinstating him as Prime Minister and acting President. The Court stated that it found no evidence of Han's involvement in President Yoon’s decision to impose martial law.

Sources: The Korea Herald, Human Rights Watch, BBC News, Al Jazeera, Chatam House, The New York Times

On 31 December, the Seoul Western District Court approved a request from the Corruption Investigation office for High-Ranking Officials to issue a warrant against President Yoon Suk-Yeol on charges of insurrection, treason and abuse of power after his failed martial law order on 3 December. The charges are separate from his impeachment proceedings and the warrant was issued after Yoon ignored three summonses to appear for questioning over his martial law declaration. Although past officeholders have been impeached, Yoon is the first sitting president to face an arrest.

Update: Following President Yoon’s indictment and arrest in mid-January, the Seoul Central District Court lifted his arrest warrant on 7 March 2025, stating that his detention was procedurally flawed. While allowing for his release from detention, Yoon still faces trial on insurrection charges later this year. 

Sources: International IDEA,  BBC News, The Korea Times, BBC News