Takumi Yamazaki is a Japanese voice actor and sound director born on April 14, 1964, in Tokyo, Japan. His real name is Isao Yamazaki. He began his career in 1985 and is currently represented by the agency T.S.P., where he also serves as a representative director.

Yamazaki's path to voice acting was shaped by early aspirations of flight. As a child, he dreamed of becoming a bird, and later, a fighter pilot with hopes of becoming an astronaut. Although he had to abandon this path due to poor eyesight, his interest in performance was sparked in high school when he helped friends in the drama club, eventually taking on roles in scriptwriting and stage work. He was drawn to the unique challenge of expressing character solely through voice, which led him to pursue professional training. He graduated from the Haikyo Acting Institute's 14th term and the Baobab Academy (now Visual Space Voice Actor Training School) 4th term.

Yamazaki is known for his resonant baritone voice, which he has described as a "human loudspeaker," a quality honed through his stage experience. This powerful and penetrating voice allows him to portray a wide spectrum of characters, from serious heroes and villains to comedic roles and even animal characters, with equal skill.

A significant aspect of Yamazaki's career is his succession of many roles originally performed by the late voice actor Kaneto Shiozawa. The two were close friends, and Yamazaki has taken on this responsibility with deep respect. Notable examples include the character Aries Mu in the Saint Seiya franchise, a role he first took on in Saint Seiya: The Hades Chapter and has since reprised in later works like Saint Seiya: Soul of Gold. He also succeeded Shiozawa as M'Quve in the Mobile Suit Gundam: The Origin OVA series and the film Mobile Suit Gundam: Cucuruz Doan's Island, a performance that earned high praise from the series' director, Yoshikazu Yasuhiko.

Yamazaki's extensive filmography demonstrates his versatility and longevity in the industry. He has held lead roles in landmark series, such as the hot-headed test pilot Isamu Alva Dyson in Macross Plus, a part he considers particularly significant for fulfilling his childhood dream of flying. In a starkly different vein, he has been the voice of Torippii Sorano, the cheerful green parrot, in the long-running children's educational series Shimajirō since 1993, a role so iconic that it is considered a third aspect of his public persona.

His ability to move between genres is evident in his many other prominent roles. He played the noble Knight George de Sand in Mobile Fighter G Gundam and the mysterious Ferio in Magic Knight Rayearth. He has also taken on villainous or antagonistic roles, such as the cunning Kayneth El-Melloi Archibald in Fate/Zero, the musician Bansai Kawakami in Gintama, and Kurozumi Kanjuro in One Piece. In more recent years, he has voiced the Kasugai Crow for the protagonist Tanjiro in the global phenomenon Demon Slayer: Kimetsu no Yaiba and Dread in the popular series BOFURI: I Don't Want to Get Hurt, so I'll Max Out My Defense.

Beyond acting, Yamazaki is also active as a sound director and is dedicated to nurturing new talent. He serves as a lecturer at the Nihon Kogakuin College and has been the principal of the Nyokki Studio voice actor school since 2014.