SEOUL—South Korea’s Constitutional Court ousted President Yoon Suk Yeol over his short-lived declaration of martial law, clearing the way for a snap vote to elect a new president who will contend with deep divisions at home and rising friction with the U.

The South Korean Constitutional Court’s decision to formally unseat President Yoon Suk Yeol is another test for the country’s democracy after the conservative-liberal divide deepened over his imposition of martial law and subsequent impeachment.

South Korea’s Constitutional Court removed impeached President Yoon Suk Yeol from office on Friday, ending his tumultuous presidency and setting up an election to find a new leader, four months after he threw South Korean politics into turmoil with an ill-fated declaration of martial law.