Kōhei Yamashita is a Japanese voice actor known for work in anime dubbing, video games, and foreign film localization. He was born on March 20 and is from Hyogo Prefecture, Japan. In the anime series Sockie's Frontier Quest, Yamashita provides the voice for the character of the Wizard, also referred to as the Sage or Master of Magic.

Yamashita is active as a voice actor primarily in the field of dubbing for foreign television dramas and movies. In addition to his performance work, he has extensive experience as a voice acting instructor, having taught at vocational schools and training institutes for ten years. He continues to teach at institutions such as NAYUTAS and Human Academy, and he also hosts an afterschool recording workshop called Gembakai. He is in a business partnership with the talent agency Leopard Steel.

His anime voice credits include the role of Alastor in Hazbin Hotel, Steve in BIGTOP BURGER, the one-eyed crow in Cat's Dayan, and a职员 (staff member) in Shadowverse F. He also performed the role of a character named Unko Hayama in Unko-san Junjouha. In the comedy anime DAME na Watashi ni Koishite Kudasai, he played Kuratama's ex-boyfriend.

Within the video game industry, Yamashita has contributed to several titles. He voiced Wataru Meguriya in Urban Legend Dissolution Center and the character Behirun in Echo of Soul. His other game roles include Cort in Hoshiai no Metria, Izalq in Alchemia Story, and Vision in Farlight 84. He also provided voices for characters in games such as Auto Chess, Detective Opera Milky Holmes, Scarlet Rider Zexs, and三国志 Grand Bout.

Yamashita has an extensive list of dubbing credits for foreign media, known in Japan as gaiga. He provided the Japanese voice for Chad in the American series Homecoming Season 2 and the role of Jacob in the film Mile 22. Additional dubbing work includes roles in Truth: Dark Prosecution, The Convent, MacGyver Season 4, and the Chinese television series Swords of Legends.