Atsushi Miyauchi is a Japanese actor and voice actor born on July 8, 1969, in Saitama Prefecture, Japan. He is affiliated with the talent agency Miki Production. Standing 177 cm tall with blood type O, his professional skills include horse riding, sword fighting, and holding a second dan black belt in Shorinji Kempo.

Miyauchi's path to acting began during a period as a ronin, a student preparing for university entrance exams, when watching the film Angel Heart in a cinema inspired him to pursue performance. He entered the acting profession in the early 1990s, starting with minor roles in theater productions. A significant early live-action role came in 2000 when he was selected from 2,000 applicants to play the lead role of a young Miyamoto Musashi in the historical film MUSASHI. He also appeared in supporting parts in NHK taiga dramas such as Musashi (2003) and Yoshitsune (2005).

His transition to voice acting began around 2000, encouraged by a senior colleague at his agency who had already found success in the field. His distinctive deep and rough vocal timbre proved well-suited for the demands of dubbing foreign films and voicing characters in anime. His initial voice work involved dubbing villain roles in Hong Kong films. His first anime credit was a minor role in Kaze no Yojimbo in 2001. He gradually built his presence in the anime industry throughout the early 2000s, with his first major supporting anime role coming as Masamori Sumimura in the series Kekkaishi (2006-2008), a part that also included narration duties and helped establish him as a prominent voice actor.

Miyauchi's career encompasses a wide range of roles in anime, animated films, and video games. Among the many characters he has voiced are, including Mack, a boxer who stages a miraculous comeback with cutting-edge technology, in Megalobox 2: Nomad; Daiju Mononobe, a key character known as Seleção No. 1, in the Eden of the East series, including the television show, the films The King of Eden and Paradise Lost, and Air Communication; Vinsmoke Niji, one of Sanji's brothers, in the long-running series One Piece; and Lu Bu (Ryo Fu) Tallgeese in both the SD Gundam Sangokuden Brave Battle Warriors television series and its film adaptation. He also voiced Sergio Caldone in Lupin III Italian Game; Tadashi Miyanomori in the OVA and drama CD for Hanayaka Nari, Waga Ichizoku; and Leon in Battle Spirits: Shōnen Gekiha Dan.

Other notable anime roles include the sadistic assassin Cioccolata in JoJo's Bizarre Adventure: Golden Wind; Yu Jin in Tokyo Revengers; Geil Hunt in Mobile Suit Gundam 0083: Stardust Memory - The Mayfly of Space 2; and Lernen in Frieren: Beyond Journey's End. In film, he voiced Egba Atler in Mobile Suit Gundam: Cucuruz Doan's Island and has had roles in various Ghost in the Shell films. His video game work includes the character Yu Jin in the Dynasty Warriors 8 series and Ash in Stranger of Paradise: Final Fantasy Origin.

Beyond anime and games, Miyauchi has achieved recognition for his extensive dubbing work. A major milestone is his consistent role as Bruce Banner and the Hulk, voicing Mark Ruffalo in the Japanese versions of the Marvel Cinematic Universe films, beginning with Avengers: Age of Ultron in 2015. He has also dubbed performances for actors such as Karl Urban, Christian Bale, and Tom Hardy. His live-action career has continued alongside his voice work, with appearances in films and television dramas. As of 2025, Miyauchi remains active in the industry, taking on roles in new anime series and video games.