The 4th Local Elections were held in South Korea on 31 May 2006. It was the first local elections in South Korea to have political parties nominating candidates for Municipal Councillors. The ruling Uri Party proved its declining popularity since the 2004 general elections while the main opposition party, Grand National Party managed to clinch back lost grounds, using the opportunity for the presidential election the following year.

The Liberty Korea Party (Korean: 자유한국당) was a conservative political party in South Korea that was described variously as right-wing, right-wing populist, or far-right. Until February 2017, it was known as the Saenuri Party, and before that as the Hannara Party from 1997 to 2012, both of which are still colloquially used to refer to the party. The party formerly held a plurality of seats in the 20th Assembly before its ruling status was transferred to the Democratic Party of Korea on 27 December 2016, following the creation of the splinter Bareun Party by former Saenuri members who distanced themselves from President Park Geun-hye in the 2016 South Korean political scandal.