The Corruption Investigation Office for High-ranking Officials (Korean: 고위공직자범죄수사처; Hanja: 高位公職者犯罪搜査處; RR: Gowigongjikja beomjoesusacheo), or CIO in short, is an independent agency of the South Korean government responsible for prosecuting crimes and investigating allegations involving "high-ranking officials" or their direct family members.

The Act specifies the posts as high-ranking government officials, including but not limited to parliamentarians, prosecutors, judges and even the President.

[2] The Act on the establishment and operation of the CIO was passed by the National Assembly in December 2019[3] and entered into force in July 2020.

[1] In February 2020, the Constitutional Court of Korea agreed to hear the case filed by the opposition party against its establishment.

The amended Act now requires the nomination committee to form only 5 of the 7 total possible votes - effectively removing veto power of the opposition party - to choose the final two candidates.