A Seoul court sentenced former President Yoon Suk Yeol to life imprisonment with hard labor on Thursday after finding him guilty of leading an insurrection through his short-lived declaration of martial law in December 2024, marking the most severe punishment ever imposed on a South Korean head of state in the democratic era.

The Seoul Central District Court ruled that Yoon, 65, masterminded a grave attack on constitutional order by mobilizing troops to surround the National Assembly, attempting to arrest political opponents and seizing control of the national election commission during the six-hour crisis on Dec. 3, 2024. Prosecutors had sought the death penalty, arguing the actions threatened decades of democracy, but the court opted for life imprisonment, noting the plot’s failure to cause casualties or widespread violence.

Yoon, who served as president from May 2022 until his removal in April 2025, was impeached by the National Assembly on Dec. 14, 2024, just 11 days after the martial law order. The Constitutional Court upheld the impeachment unanimously on April 4, 2025, ousting him from office. He became the first sitting president in South Korean history to face arrest in January 2025 and has been in custody since July 2025 while facing multiple trials.
The insurrection charge carried the heaviest penalty among several related indictments.

Yoon claimed the martial law was necessary to combat “anti-state forces” and alleged election fraud, but provided no evidence. The court described the episode as an “insurrection from the top,” involving senior officials including former Prime Minister Han Duck-soo (sentenced to 23 years last month), ex-Defense Minister Kim Yong-hyun (30 years) and others jailed for their roles.

Yoon is already serving a five-year term from a January 2026 ruling for abuse of power, obstructing arrest and related offenses tied to the martial law declaration. He faces at least three more trials on additional charges. His legal team is expected to appeal the life sentence within a week, though analysts anticipate prolonged proceedings.

The verdict caps a tumultuous period that plunged South Korea into its worst political crisis in decades, testing democratic institutions and exposing deep polarization. Yoon’s supporters rallied outside the courthouse, while critics celebrated the ruling as accountability for an unprecedented power grab.

The martial law attempt — Yoon’s declaration on live television to root out alleged threats — triggered immediate backlash, with lawmakers reconvening to vote it down within hours. The episode led to Yoon’s impeachment, removal and a snap presidential election in June 2025, won by opposition leader Lee Jae-myung of the Democratic Party.

Yoon’s presidency, marked by conservative policies, tensions with North Korea and domestic scandals, ended amid the fallout. His conviction makes him the first elected South Korean leader to receive a life sentence, though the country has not executed anyone since 1997 despite retaining capital punishment.

Reactions poured in Thursday: President Lee Jae-myung remained silent, while opposition figures hailed the decision as upholding democracy. Supporters decried it as politically motivated. The ruling could influence South Korea’s political landscape ahead of future elections, with Yoon disqualified from public office for five years under separate penalties.
As Yoon begins serving the life term, the case underscores the resilience of South Korea’s democracy amid a grave constitutional challenge.