John Gremillion is an American voice actor known for his extensive work in English-language dubs of Japanese anime series and video games. He was born John Michael Gremillion on June 11, 1967, in Houston, Texas. He pursued higher education in the arts, studying film at the University of Texas at Austin and later training in drama at the prestigious Juilliard School.

Gremillion's career in voice acting has spanned several decades, with his involvement in anime dating back to the late 1990s. Over this period, he has become a familiar voice for audiences through his work with major production companies, including ADV Films, Funimation, and Sentai Filmworks. In addition to his voice work, he has also worked as a professional video editor, contributing to supplemental materials for releases such as Halo Legends.

His filmography is extensive, encompassing a wide array of characters across numerous popular series. He is particularly recognized for his long-standing role as the powerful and stoic swordsman Dracule Mihawk in the Funimation dub of the long-running series One Piece, a role he has also reprised in films like One Piece Stampede. Another notable and recurring character is the Level 6 adventurer Ottar in the Is It Wrong to Try to Pick Up Girls in a Dungeon? franchise. He has also taken on significant antagonist roles, such as the well-intentioned but misguided villain Gentle Criminal in My Hero Academia.

His range as a voice actor is evident in the diversity of his other prominent credits. These include the complex Albedo Piazzolla in Xenosaga: The Animation, the protagonist Hakuoro in Utawarerumono, Cardinal Francesco de Medici in Trinity Blood, Arthur Randall in Black Butler, Yamato Hotsuin in Devil Survivor 2: The Animation, and Takeshi Hirokawa in Parasyte -the maxim-. He has also appeared in acclaimed series such as Vinland Saga, where he voiced the characters Halfdan and The Ear, and The Heike Story, as Taira no Shigemori.

In recognition of his work, Gremillion received a nomination for the BTVA (Behind The Voice Actors) Award for Best Male Lead Vocal Performance in an Anime Feature Film/Special for his portrayal of the titular character in Sentai Filmworks' redub of the classic film Vampire Hunter D. He remains active in the industry and is a frequent guest at anime conventions across the United States.