Takayuki Yamaguchi is a Japanese voice actor born on December 28, 1975, in Chiba Prefecture, Japan. He is affiliated with the talent management firm 81 Produce and has been active in the voice acting industry since 1998.

Yamaguchi has built a career spanning numerous anime television series, original video animations (OVAs), and video games, often portraying supporting characters. One of his most enduring roles is Yūta Izaki in the long-running Cardfight!! Vanguard franchise, a character he voiced across multiple series and installments from 2011 onwards. Another significant early role was as Kazuki Yotsuga in the 1999 series Dual! Parallel Trouble Adventure and its subsequent special. He also voiced the character Kazuki Mizuki in the anime adaptation of Salaryman Kintaro.

His film work includes providing a voice for the 2018 animated film Engimon, where he played the character Fukujirō. In the fantasy comedy Petite Princess Yucie, he voiced the character Arc. His repertoire also features roles such as Kazuya Saotome in Hand Maid May, Kyousuke Aoki in Strawberry Eggs, Shindara in Samurai Deeper Kyo, Clove in The Marshmallow Times, and Tom in.hack//Legend of the Twilight.

Beyond anime, Yamaguchi has contributed his voice to several notable video games. He performed multiple roles in the critically acclaimed Final Fantasy X, voicing the characters Brother, Clasko, Keepa, and Wantz. He reprised the roles of Brother and Clasko in its direct sequel, Final Fantasy X-2. He also voiced the character Leonhart in the PlayStation version of Final Fantasy II. His work extends to foreign language dubbing of animated series, where he provided the Japanese voice for Muck in Bob the Builder and a character in CatDog.