K4 League

The K4 League is the fourth-highest division in the South Korean football league system. It is regarded as the successor to the K3 League Basic, the second division of amateur K3 League founded in 2017.

Since 2021, Korea Football Association has allowed reserve teams of the K League to join the K4 League.

Competition format
All participating clubs play home and away season in the K4 League. The promotion and relegation system exists between the K3 League and the K4 League, but does not exist between the K4 League and amateur league K5 League. The champions and runners-up can be directly promoted to the K3 League, and third and fourth-placed teams qualify for the first round of the promotion playoffs.

Former clubs
The following clubs are not in the K4 League as of the 2024 season.