The K3 League is a top amateur football competition in South Korea. Created in 2007, it is the third tier of South Korean football league system.
2007 was the inaugural season of the K3 League, and ten teams competed in the competition.
The season operated a two stage system, with each side playing each other once in each stage for a combined total of eighteen matches (nine in each stage). The winners of both stages, Hwasung Shinwoo Electronics FC and Seoul United respectively, plus the two teams with the best overall record from both stages, Cheonan FC and Yong-in FC, entered the championship playoffs. Seoul United emerged victorious in the championship playoffs, defeating Hwasung Shinwoo Electronics FC 3-0 on aggregate. The four playoff teams earned a spot in the 2008 FA Cup competition.
Seven new clubs registered ahead of the 2008 season with just one of the founder members, Daegu Korea Powertrain, withdrawing from the league set-up.
After 1st stage of the 2008 season, Changwon United was withdrawn the league due to financial problem. At the end of the 2008 season, Seoul Pabal FC was closed because some players of Seoul Pabal FC were implicated in the K3 Leauge Match Fixing Scandal.
From the 2009 season, 17 clubs competed the league due to three new clubs registered.
On December 1, 2009, Korea Football Association has announced that Seoul Yangcheon FC, Yeonggwang FC & Chuncheon Citizen FC will join the league for the 2010. And, KFA has also announced that an undergraduate never play the league game from the 2012 season and top nine teams of league earned a spot in next year FA Cup competition. On January 15, 2010, KFA has announced the league schedule in the 2010 season. Seoul Yangcheon FC is postponed joining the league to the 2011 season. And, Jeonju Ongoeul FC is defucted from the 2010 season.
In 2008 season, it operates its season in two stages, with the winners of each stage and the two runners-up advancing to the post-season championship playoffs. If in the event of the same team winning both stages, there will be no playoff.
In 2009 season, championship playoff was abolished. Each club plays the others twice, once at their home stadium and once at that of their opponents, for a total of 32 games.
The 2010 season runs from March 13 through October 30. The 18 teams in the league are divided into the Group A and Group B — eight in the Group A, eight in the Group B. Each team competes against the other team in same group twice, home and away, the other group’s team once, home or away, for a total of 25 games. The two group winners and two runners-up qualify to the Championship playoff.