South Korea Supreme Court affirms seven-year jail term for former President Yoon

South Korea’s Supreme Court has upheld the seven-year prison sentence imposed on former President Yoon Suk Yeol over offences connected to his failed martial law declaration in 2024 and subsequent attempts to obstruct investigations into the episode.

The ruling, delivered on Thursday, marks another major legal setback for the disgraced former leader, who is already behind bars while challenging a separate life sentence for insurrection arising from the same political crisis.

The country’s highest court dismissed appeals filed by both prosecutors and Yoon’s legal team, effectively affirming the judgment of a lower appeals court that had increased his prison term from five to seven years.

The case focused on allegations that Yoon bypassed established government procedures before declaring martial law in December 2024 by consulting only a select group of cabinet members rather than convening a full cabinet meeting.

Prosecutors also accused him of authorising the creation and destruction of a false martial law decree carrying forged signatures attributed to the prime minister, disseminating misleading information to foreign media and ordering the deletion of sensitive military records.

Additional charges stemmed from claims that presidential security personnel were deployed to prevent investigators from executing an arrest warrant after lawmakers voted to nullify the martial law declaration.

In its ruling, the Supreme Court found no grounds to overturn the lower court’s decision.

“All appeals are dismissed,” the presiding judge said during the televised proceedings, adding that the judgment under review contained no legal errors.

Prosecutors had sought a 10-year prison term, arguing that the former president abused his office and undermined democratic institutions.

Yoon’s lawyers, however, criticised the ruling, expressing “deep regret” and accusing the court of failing to adequately consider the defence’s arguments. They indicated plans to pursue further constitutional challenges.

The legal troubles facing the former president stem from the dramatic events of December 2024 when he announced martial law during a late-night national address, temporarily suspending civilian rule and triggering widespread political turmoil.

The declaration lasted only a few hours before lawmakers convened an emergency session and voted to overturn it.

The move sparked nationwide protests, unsettled financial markets and raised concerns among South Korea’s international partners, including the United States.

Yoon has consistently defended his actions, maintaining that the declaration was necessary to protect national interests, combat what he described as anti-state elements and respond to perceived security threats from North Korea.

Beyond the seven-year sentence upheld on Thursday, the former president is appealing a separate life sentence imposed after he was convicted of leading an insurrection through the martial law declaration.

He has also been handed a 30-year prison term in another case involving allegations that he authorised drone operations into North Korea in an attempt to manufacture a security crisis ahead of imposing martial law.

The political fallout from the crisis ultimately led to Yoon’s removal from office in April 2025.

His impeachment paved the way for fresh elections, which were won by Lee Jae Myung of the centre-left Democratic Party of Korea, ushering in a new administration after one of the most turbulent periods in South Korea’s recent political history.