Brian Mathis is an American voice actor born on December 29, 1964, recognized for his extensive work in English dubs of Japanese anime series. His career has been primarily associated with major production companies in the industry, including Funimation Entertainment, Crunchyroll, OkraTron 5000, and Sentai Filmworks.

Mathis has built a substantial portfolio of voice roles, often portraying authoritative, paternal, or experienced characters. Among his most prominent and widely recognized roles is Monkey D. Garp, the legendary Marine vice-admiral, in the long-running series One Piece. He has voiced this character across various One Piece productions, including the main television series, the special One Piece 3D2Y: Overcoming Ace's Death! Luffy's Pledge to His Friends, and several films such as One Piece: Strong World, One Piece Film Z, and One Piece: Stampede.

Another signature role for Mathis is Elias Ainsworth, the enigmatic, skull-headed mage and titular character in The Ancient Magus' Bride. He also voiced the stern water polo coach Akimitsu Bizen in the sports anime RE-MAIN and the grizzled veteran tanker Minato in the sci-fi series Deca-Dence. His other notable leading and supporting roles include the commanding officer Gustav Honda in Fire Force, the strategist Hagal in The Genius Prince's Guide to Raising a Nation Out of Debt, the mage Chester Ray Galford in How NOT to Summon a Demon Lord and its sequel, and the mysterious Kongo in Land of the Lustrous.

In the science fiction and fantasy genres, Mathis has provided voices for characters such as the warrior Vidaux Volker in RErideD: Derrida, Who Leaps Through Time, the priest Quo Vadis Pater in Sorcerous Stabber Orphen: Battle of Kimluck, the cunning Oda Nobunaga in Samurai Warriors: Legend of the Sanada, and the operative Ben in Strain: Strategic Armored Infantry. He also voiced the character Yasuomi Ōno in the badminton-themed series Salaryman's Club and the sinister Rizo Nakimoto in A Certain Scientific Accelerator.

His career also includes a wide array of significant supporting roles in major series. These include Macao Conbolt in Fairy Tail, Sauros Boreas Greyrat in Mushoku Tensei: Jobless Reincarnation, Juzo Okita in Star Blazers: Space Battleship Yamato 2199, and various characters in long-running franchises like the narrator and additional roles in the Sengoku Basara series and Doppo Orochi in a Sentai Filmworks dub of Baki.

Throughout his career, Mathis has frequently collaborated with the pool of voice talent based in Texas, where Funimation and related studios are located. His work demonstrates a long-standing and prolific partnership with these companies, contributing his voice to hundreds of episodes and numerous films across a diverse spectrum of anime genres, from action and fantasy to drama and science fiction.