K3 League
The K3 League is a football competition in South Korea. Created in 2020, it is considered the third tier of South Korean football league system. After the 2019 season, the former Korea National League and K3 League Advanced became defunct and were rebranded into the K3 League.
History
In 1964, a semi-professional league that existed until 2002 was started with the Korean National Semi-Professional Football League. In 2003, it was replaced by the Korea National League. Over time, more and more associations joined the association. Meanwhile, 15 clubs played in one match at the KNL. With the establishment of the K League Challenge as second-tier professional league in 2013, the number of clubs in the KNL has decreased. Since 2017, only eight clubs have participated to the league. At the same time, the amateur league K3 league has developed into a promotion and relegation league. In 2015, the Korea Football Association 's structural reform plan will be announced to merge the KNL and K3 leagues. In late 2019, both the Korea National League and K3 leagues were disbanded, replaced by two new class profiles; K3 League and K4 League. In 2020, the K3 League was launched with a total of 16 teams, with eight teams in the KNL, seven teams in the K3 League Advanced, and one team in the K3 League Basic.Competition format
The promotion and relegation system exists between the K3 League and the K4 League.In 2020, the K3 League will have 16 teams played one stage double round-robin again total 30 of games. Teams will not be able to promote to the higher tier since the K League 2 is played under the different league system. However, the teams will be able to get relegated to the K4 League.
Clubs
The following 16 clubs will compete in the K3 League during the 2020 season.The following sixteen clubs will compete in the K3 League during the 2020 season, including all eight teams from the 2019 KNL of the now defunct Korea National League, six teams from the 2019 K3 League Advanced and two teams from the 2019 K3 League Basic.
| Team | City | Stadium | Founded | Joined | Head Coach | Position |
| Busan TC FC | Busan | Busan Gudeok Stadium | 2006 | 2020 |  Park Sang-In | 5th in the 2019 N League |
| Changwon City FC | Changwon | Changwon Football Center | 2005 | 2020 | Park Hang-seo | 8th in the 2019 N League |
| Cheonan City FC | Cheonan | Cheonan Football Center | 2008 | 2020 | Kim Tae-young | 2nd in the 2019 N League |
| Cheongju FC | Cheongju | Heungdeok Football Park | 2004 | 2020 | Seo Won-sang | 9th in the 2019 K3 Advanced |
| Chuncheon FC | Chuncheon | Chuncheon Stadium | 2010 | 2020 | Kim Yong-ho | 10th in the 2019 K3 Advanced |
| Daejeon Korail FC | Daejeon | Daejeon Hanbat Sports Complex | 2003 | 2020 | Kim Seung-hee | 4th in the 2019 N League |
| Gangneung City FC | Gangneung | Gangneung Stadium | 2003 | 2020 | Park Moon-Young | 1st in the 2019 N League |
| Gimhae FC | Gimhae | Gimhae Public Stadium | 2008 | 2020 | Kim Gwi-Hwa | 7th in the 2019 N League |
| Gimpo Citizen | Gimpo | Gimpo City Stadium | 2013 | 2020 | Yoo Jong-wan | 4th in the 2019 K3 Advanced |
| Gyeongju Citizen | Gyeongju | Gyeongju Civic Stadium | 2008 | 2020 | Kim Jin-hyung | 2nd in the 2019 K3 Advanced |
| Gyeongju KHNP | Gyeongju | Gyeongju Civic Stadium | 2003 | 2020 | Uh Yong-kuk | 3rd in the 2019 N League |
| Hwaseong FC | Hwaseong | Hwaseong Stadium | 2013 | 2020 | Kim Jong-boo | 1st in the 2019 K3 Advanced |
| Jeonju Citizen | Jeonju | Jeonju Stadium | 2007 | 2020 | Jung Jin-hyuk | 2nd in the 2019 K3 Basic |
| Mokpo City FC | Mokpo | Mokpo International Football Center | 2010 | 2020 | Kim Jung-Hyuk | 6th in the 2019 N League |
| Pyeongtaek Citizen | Pyeongtaek | Sosabeol Reports Town | 2017 | 2020 | Lee Ho-joon | 11th in the 2019 K3 Advanced |
| Yangju Citizen | Yangju | Yangju Stadium | 2007 | 2020 | Lee Seung-hee | 3rd in the 2019 K3 Basic |