The 2015–16 Top League Challenge Series was the 2015–16 edition of the Top League Challenge Series, a second-tier rugby union competition in Japan, in which teams from regionalised leagues competed for promotion to the Top League for the 2016–17 season.
There was no automatic promotion to the 2016–17 Top League, but Kyuden Voltex, Mitsubishi Sagamihara DynaBoars, Munakata Sanix Blues and Osaka Police progressed to the promotion play-offs.
All four teams in Challenge 1 qualified to the promotion play-offs.
The final standings for the 2015 Top West League were:[1] The final standings for the 2015 Top East League were:[2] The final standings for the 2015 Top Kyūshū League were:[3] The final standings for the 2015–16 Top League Challenge 1 were:[4] The following matches were played in the 2015–16 Top League Challenge 1:[4]
The final standings for the 2015–16 Top League Challenge 2 were:[4] The following matches were played in the 2015–16 Top League Challenge 2:[4]