Tetsuya Oka is a male Japanese voice actor born on September 17 and affiliated with the talent agency Production Ace. Hailing from Kyoto Prefecture, his skills include speaking the Kansai dialect as well as hobbies such as cooking, CD drama editing, model making, and script writing.

Oka is primarily known for his extensive work in dubbing foreign films and television series, which forms the core of his career. He provided the Japanese voice for the character Assistant in the 2011 film Transformers: Dark of the Moon. His notable dub credits include roles in major Hollywood productions such as Kick-Ass playing Marty Eisenberg, Iron Man 2, Captain America, The King's Speech, and Total Recall. In television, he has dubbed roles in series like House playing Taub, Pretty Little Liars as Ted, House of Cards, Mad Men, and the Korean drama series Three Kingdoms as Xiahou Yuan.

In anime, Oka has appeared in a variety of supporting roles. He is known for playing Ohba in the horror series Another, Kenji Hotta and Yamai in the soccer anime Giant Killing, Hatsuma Fushimi in Inari Kon Kon, and a referee in Prince of Stride: Alternative. He also lent his voice to characters in shows like Is This a Zombie?, The Eccentric Family, and the international co-production Power Rangers Mystic Force.

Oka has a notable presence in the video game industry, particularly within major Western franchises. He provided voices for characters in several entries of the Assassin's Creed series, including Black Flag and Syndicate, as well as Call of Duty: Black Ops 3, Destiny, and Fallout 4. He is also active in audio books and voice-over narration for documentary programs.