Ryo Oshima is a Japanese voice actor and singer, born on September 18, 1991, in Tochigi Prefecture. He is best known for his role as Ushio Toujou in the anime and multimedia franchise Gokujō!! Mecha Mote Iinchō.

Oshima's most prominent and defining career role was as a regular cast member in the television Tokyo series Gokujō!! Mecha Mote Iinchō, where he voiced the character Ushio Toujou from April 2009 to March 2011. He continued this role in the subsequent series, Gokujō!! Mecha Mote Iinchō Second Collection. His involvement with the franchise extended beyond voice acting. As a member of the unit MM3, formed within the series, he performed theme songs and contributed to the franchise's music. MM3 released several CDs, including the debut single Kokoro, Kimi ni Todoke in October 2009 and the second single Kono Te no Naka ni in June 2010. He also participated in live events and stage productions related to Mecha Mote Iinchō, such as the live performance and the stage play Mecha Mote Gekijō in 2011.

His professional activities also included work in other areas of entertainment. He appeared on the television program Oha Suta on TV Tokyo. In radio, he hosted his own show, Ryo Oshima no Home Room ni Shuugou!, on FM Tochigi. He was also a regular personality on the cultural broadcasting and A&G+ program A&G Artist Zone 2h. Additionally, he appeared in web-based programs such as Air Raid's Ryo Oshima no Voice Jack! and TBS Radio's Aneki to Boku no Healthy Cooking!. His stage work included a role in the 2011 production Prince Seven -Futsuu no Ouji wo Buttobase!!-.