[1] This exceeded the required two-thirds threshold in the National Assembly and, although the vote was by secret ballot, the results indicated that more than half of the 128 lawmakers in Park's party Saenuri had supported her impeachment.

According to Article 65 Clause 1, if the president, prime minister, or other state council members violate the Constitution or other laws of official duty, the National Assembly can impeach them.

Clause 2 states the impeachment bill must be proposed by one third, and approved by a majority of members of the National Assembly for passage.

[14][15][16] On 25 October 2016, Park apologized to the nation in a televised address from the Blue House for giving Choi access to draft speeches during the first months of her presidency.

[20] The response to the Sewol ferry sinking accident that occurred on 16 April 2014 also contributed to Park's declining presidential ratings.

[8] President Park held a final cabinet meeting acknowledging the impeachment motion and apologised for causing uncertainty, before Prime Minister Hwang Kyo-ahn assumed presidential powers and duties at 19:30 Korean Standard Time, on an interim basis.

[27][28] On 1 January 2017, Park appeared in public for the first time since the impeachment before a select group of reporters at the Blue House, saying she denied any allegations of the scandal and wrongdoings.

The administration's delayed response to the disaster led to widespread criticism in South Korea and forced Park to deny various rumours.

[34][35] Then, on 23 December the Justice Ministry of South Korea said that it has submitted its views on the recent parliamentary vote to impeach President Park Geun-hye to the Constitutional Court, adding that the process has met all the necessary legal requirements.

[36] The Constitutional Court was to officially start the main hearings on Tuesday, 3 January 2017,[37] and Park would not be required to appear for questioning.

This opened the possibility of Park's indictment if the Constitutional Court upheld the National Assembly's impeachment motion,[41] which it ultimately did.

On 10 March 2017, 11.00 am KST, the Constitutional Court upheld the impeachment in a unanimous 8–0 decision read out by Acting Chief Justice Lee Jung Mi, formally ending Park's presidency.

"[42][43] This marked the first time that a sitting president was removed from the office since the creation of the Sixth Republic of South Korea after the country's democratization in 1987.

[44][45] As a result of impeachment, Park was stripped of her post-presidential benefits such as retirement pension, free medical services, state funding for her post-retirement office, personal assistants and a chauffeur, and right to burial at the Seoul National Cemetery after death.

She was arrested and placed into custody after an indictment by prosecutors on charges of bribery, abuse of power, coercion, and leaking government secrets on 31 March.

[48] In July 2018, it emerged that the Defense Security Command made plans for declaring martial law and authority to use military force to crackdown on protesters, if the Constitutional Court did not uphold Park's removal from office.

[49] The DSC had planned to mobilize 200 tanks, 550 armoured vehicles, 4,800 armed personnel, and 1,400 members of special forces in Seoul in order to enforce martial law.

Other components of the plan included monitoring and censoring media content and arresting politicians taking part in protests.