On 27 December 2024, South Korean prime minister and acting president Han Duck-soo was impeached. The impeachment occurred 13 days after President Yoon Suk Yeol had been impeached as a result of his brief enactment of martial law, making Han acting president.

Opposition Democratic Party Floor Leader Park Chan-dae announced plans to impeach Han on 24 December following his veto of two special counsel bills investigating Yoon and First Lady Kim Keon-hee. On 26 December, the impeachment motion was formally introduced after Han blocked the appointment of three justices to the Constitutional Court of Korea, whose nominations had been approved by the National Assembly.

On 27 December, all 192 opposition Assembly members unanimously voted in favor of Han's impeachment, after Speaker Woo Won-shik ruled that, as a cabinet minister, Han's impeachment was subject to a simple-majority rule. The remaining 108 Assembly members, all from Yoon's People Power Party (PPP), boycotted the vote. Deputy Prime Minister and Finance Minister Choi Sang-mok assumed the roles of acting president and acting prime minister pending the Constitutional Court's decision on Han's removal from office.

On 24 March 2025, the Constitutional Court voted to overturn Han's impeachment, reinstating him as acting president and prime minister.

The 1987 constitution established South Korea as a presidential democracy. At the time of Han's impeachment, only one Korean president has been removed from office through impeachment (Park Geun-hye in 2017), which requires a two-thirds majority voting in favor in the legislature. Former president Roh Moo-hyun was impeached in 2004, but the Constitutional Court acquitted him of two infractions and deemed the remaining charge not serious enough to warrant removal, allowing him to remain in office.

The procedure for impeachment was established in the 10th Constitution of South Korea (1987) Article 65, Clause 1, specifies that the National Assembly may impeach the president, prime minister, or other state officials if they violate the constitution or other laws while performing official duties.

For an impeachment motion against a sitting president to pass, a two-thirds majority of the National Assembly – 200 out of 300 members – must vote in favor. Once passed, the individual is immediately suspended from their duties pending a ruling by the Constitutional Court of Korea. The scope of impeachment is limited to removal from public office, with no further penalties imposed through this process. However, as Han is an acting president, disputes have arisen in the National Assembly over the requirements for his impeachment. The People Power Party (PPP) argued that, since Han had assumed the role of the president, a two-thirds majority was required for impeachment. In contrast, the opposition Democratic Party (DPK) maintained that a simple majority was sufficient, as Han remained a cabinet minister. Furthermore, no laws explicitly define the requirements for impeaching an acting president.

According to the Constitutional Court Act passed in 1988, the Constitutional Court must render a decision within 180 days after it receives any case for adjudication, including impeachment cases. If the respondent has already left office before the decision, the case is dismissed. Formal removal of the president requires six of the nine justices voting in favor; due to three vacancies, all six justices would have to vote to remove him. Article 23 of the Constitutional Court Act requires at least seven justices for deliberation. On 14 October 2024, the Constitutional Court temporarily suspended the required deliberation quorum of seven justices, citing the constitutional right to a speedy trial, allowing itself to move forward.