Takanori Ohyama is a Japanese actor, voice actor, and playwright born on March 8, 1974, in Aichi Prefecture, Japan. He is affiliated with the talent agency Office Osawa. In addition to his performance work, he is also the president of the Signals theatre company, where he takes on writing and directing responsibilities.

Ohyama began his career in theatre, spending twelve years as a member of the renowned theatre company Nylon 100℃ before departing in 2009 to found his own company, Signals. His transition into anime voice acting began in the early 2000s. He is perhaps best known for his first major leading role as the otaku college student Kanji Sasahara in the anime series Genshiken, a character he portrayed across the original series, its second season, and subsequent OVAs. This role is considered a defining performance in his career.

His filmography includes a variety of supporting characters in prominent anime series. He voiced Yasunobu Hattori in Suzuka and provided the voice for the antagonist Byakuran in the long-running series Reborn!. He also played roles such as Kuroshio in Zegapain and Ikazuchimaru in Yu-Gi-Oh! GX. In a notable piece of crossover work, he voiced the character Michael in Prigorota: Uchū no Yūjō Daibōken, a fictional anime series that appears within the live-action drama and subsequent anime adaptation of Nodame Cantabile. His later anime credits include roles in Your Lie in April as Akira Takayanagi and in The Irregular at Magic High School as Isao Sekimoto. He has also lent his voice to animated films, such as Motoki Aizawa in The Anthem of the Heart. Beyond anime, his voice work extends to tokusatsu, with a guest role in Uchu Sentai Kyuranger.

Beyond acting, Ohyama has also been involved in music related to his anime roles, performing character songs such as Perfect World for his role as Byakuran in Reborn!. His long-standing career is marked by versatility across stage, animation, and live-action television.