Kantō Soccer League (関東サッカーリーグ, Kantō Sakkā Rīgu), abbreviated as KSL, is the Japanese fifth tier of league football, which is part of the Japanese Regional Leagues. It covers most of the Kantō region, as well as the prefectures of Chiba, Gunma, Ibaraki, Kanagawa, Saitama, Tochigi, Tokyo and Yamanashi. Its area is thus coextensive with the National Capital Region.

It was founded in 1967 as the Kanto Adult Soccer League and was renamed to its current name in 2000. In 2003 the KSL moved to a two-tier system and since 2012 both the first and second divisions were expanded to ten clubs. It is one of the nine regional leagues in Japan. The first division corresponds to the fifth tier and the second division corresponds to the sixth tier of Japanese football pyramid.