A woman holds a sign bearing South Korean national flag with a portrait of former President Yoon Suk Yeol, as they wait for his arrival for the final arguments in his insurrection trial, at a court in Seoul, South Korea, January 13, 2026. REUTERS
A South Korean court on Friday sentenced former president Yoon Suk Yeol to five years in prison, marking the first criminal ruling tied to his failed attempt to impose martial law in December 2024.
The Seoul Central District Court found Yoon guilty of obstructing justice by ordering the presidential security service to block investigators from executing an arrest warrant. Authorities were probing his surprise declaration of martial law, a move that lasted only hours but triggered a constitutional crisis.
Court Finds Abuse of Presidential Power
In its ruling, the three-judge panel said Yoon had abused the authority of his office by mobilizing state security personnel for personal protection and to evade legal scrutiny. The court also convicted him of fabricating official documents and bypassing required legal procedures, including failing to convene a formal cabinet meeting before declaring martial law.
“The defendant effectively privatized officials loyal to the Republic of Korea for personal safety and personal gain,” the presiding judge said during televised proceedings.
Yoon, 65, appeared in court with greying hair and a visibly slimmer frame. He showed no reaction as the sentence was read, despite the presence of many supporters in the courtroom.
Legal Team to Appeal Ruling
Yoon’s lawyer, Yoo Jung-hwa, said the defence would appeal, describing the verdict as politically motivated. Prosecutors declined immediate comment on whether they would pursue an appeal of their own.
In a separate and ongoing case, prosecutors have sought a far harsher punishment, including the death penalty, accusing Yoon of masterminding an insurrection by attempting to impose military rule without legal justification.
Former South Korean president Yoon Suk Yeol, centre, arrives at a court to attend a hearing to review his arrest warrant requested by special prosecutors in Seoul, South Korea, on July 9, 2025 (AP Photo)
Arrest, Impeachment and Fallout
Yoon is currently being held at the Seoul Detention Center. His arrest in January last year required a second attempt involving more than 3,000 police officers, after he barricaded himself inside his residence and ordered security forces to block investigators. It was the first arrest of a sitting president in South Korean history.
Within hours of his martial law declaration, parliament voted to overturn the order. Lawmakers later impeached Yoon, and in April 2025 the Constitutional Court formally removed him from office, ruling that he had violated his constitutional duties.
Political Shockwaves Continue
Although Yoon’s martial law decree lasted roughly six hours, it sent shockwaves through South Korea, a major U.S. ally and Asia’s fourth-largest economy. The case adds Yoon to a long list of former South Korean leaders who have faced imprisonment after leaving office, underscoring the country’s turbulent political history and strict accountability for presidents.
