Takeharu Oonishi (大西 健晴, Ōnishi Takeharu, born July 8, 1967) is a Japanese seiyū (voice actor) and stage actor from Nara Prefecture. He is affiliated with Arts Vision and is a founding member of the theater company Akapera. He speaks the Kansai dialect. He is married to voice actress Masayo Kurata (倉田 雅世).
2025YAIBA: Samurai Legend (11 Episodes) as Gerozaemon Geroda (voice)
2024The Fable (14 Episodes) as Kenjiro Takoda (voice)
2018Kaitou Sentai Lupinranger vs. Keisatsu Sentai Patranger (1 Episode) as Kunks Butylmercaptan (voice)
2017Case Closed: The Crimson Love Letter as Producer (voice)
2016Mobile Suit Gundam: The Origin IV – Eve of Destiny as Anaheim Electronics Plant Manager (voice)
2014Parasyte -the maxim- (1, 1 Episode) as Ancient Languages Teacher (voice), Delinquent (voice)
2012Tokumei Sentai Go-Busters (1 Episode) as Tireloid (voice)
2011Hunter x Hunter (1, 1, 2 Episode) as Cherry (voice), Tocino (voice), Worm (voice)
2010Atashin'chi: The 3D Movie as Shikai (voice)
2010Gintama: The Movie as Murata Tetsuya (voice)
2006Kekkaishi (52 Episodes) as Madarao (voice)
2006Pururun! Shizuku-chan (51 Episodes) as Ametarou (voice)
2006Intrigue in the Bakumatsu – Irohanihoheto (26 Episodes) as Kawai Tsuginosuke
2006Death Note (1 Episode) as Gukku (voice)
2005Guyver: The Bioboosted Armor (26 Episodes) as Toshiaki Hayami / Bio-Freezer (voice)
2003Crayon Shin-chan: The Glorious Storm-invoking Yakiniku Road as Taicho
2002The Boy and the Sea Turtle as Man (voice)
2002My Family (663 Episodes) as Yamamoto (voice)
2001Puni Puni Poemy (2 Episodes) as Alien 2 (voice)
1999Crayon Shin-chan: Explosion! The Hot Spring's Feel Good Final Battle as Employee (voice)
1998Popolocrois Monogatari (26, 26, 26 Episode) as Gon, Varudarosu, Daiku