The Japan national under-20 football team (Japanese: U-20サッカー日本代表) is a national association football team of Japan and is controlled by the Japan Football Association. The year before the FIFA U-20 World Cup, the national team is renamed the Japan national under-19 football team, and the year before that, the national team is renamed the Japan national under-18 football team.

Japans U20-landslag i fotball er det nasjonale fotballaget til Japan for menn under 20 år og blir administrert av Japan Football Association. Laget konkurrerer i AFC U-19-mesterskapet og FIFA U-20-verdensmesterskapet.