K3 League

The K3 League is the third-highest division in the South Korean football league system. It was run as an amateur league until 2019, but was relaunched as a semi-professional league after absorbing the Korea National League in 2020. It is currently contested by 16 clubs.

History
The Korean National Semi-Professional Football League was founded in 1964 and lasted until it was replaced by the Korea National League in 2003. The National League (K2 League) was established to introduce the promotion and relegation system between semi-professional clubs and K League clubs. However, National League clubs which formed independent federation were reluctant to invest for their professionalization, and the plan was miscarried due to their refusal.

The Korea Football Association (KFA) continued its plan to complete the South Korean football league system. The KFA made its amateur league K3 League in 2007, and introduced promotion and relegation in the amateur K3 League after dividing it into two divisions K3 League Advanced and K3 League Basic in 2017. Meanwhile, the number of National League clubs gradually decreased, while some of them joined second-tier professional league K League 2 (K League Challenge) or were dissolved due to financial problems. The K3 League Advanced and K3 League Basic were relaunched as semi-professional leagues under the name of K3 League and K4 League respectively, and the National League was merged into the newly-developed K3 League.

At present, there is promotion and relegation between the K3 League and K4 League, but clubs cannot be promoted from K3 to the K League 2. However, the KFA has announced plans to unify the K League system, meaning that from the 2027 season onwards, there will be promotion and relegation between the K3 League and K League 2.

Competition format
All participating clubs play home and away season in the K3 League. The championship playoffs were contested by top four clubs of the regular season in 2020 and 2021, but were not held in 2022 onwards. The promotion and relegation system exists between the K3 League and the K4 League, although the number of promoted team(s) and relegated team(s) is different every season.

Former clubs
The following clubs are not in the K3 League as of the 2024 season.