Monthly Shōnen Rival (Japanese: 月刊少年ライバル Hepburn: Gekkan Shounen Raibaru) was a Japanese monthly shōnen manga magazine by Kodansha that ran from April 4, 2008 to June 4, 2014. It was issued on the 4th of every month. As with Shueisha's Jump SQ. and Shogakukan's Monthly Shōnen Sunday, it is aimed at late teens and people in early twenties. Though most of the series had managed to end by the final issue, all unfinished series were transferred to online platforms such as Manga Box and New Comic Research Institute (新雑誌研究所, Shin Zasshi Kenkyūjō).