Matthew K. Miller, also known professionally as Matt K. Miller and occasionally by the stage names Kermit Miller or Kermit Beachwood, is an American actor, voice artist, and playwright. He was born on February 2, 1960. His career in voice acting is closely linked with the English dubbing of Japanese anime, particularly during the 1990s and 2000s.

Miller is most recognized for providing the English voice of Tenchi Masaki, the titular protagonist of the Tenchi Muyo! franchise. He originated this role in the Pioneer dubbing of the original Tenchi Muyo! OVA series and its associated movies, such as Tenchi Muyo! Ryo Ohki: Final Confrontations. His portrayal spanned multiple entries in the franchise, including Tenchi Muyo! In Love and Tenchi Muyo! Manatsu no Eve. He later reprised the role in 2018 for Funimation's English dub of Ai Tenchi Muyo!.

Beyond his signature role, Miller has an extensive filmography of voice work in anime. He voiced the character Sirius in the English adaptation of the Dragon Slayer OVA series. His other notable anime credits include roles in Rurouni Kenshin (as Schneider and Shuji), Mobile Suit Gundam 0080: War in the Pocket (as Andy Strauss), and Ghost in the Shell: Stand Alone Complex (as Dr. Miyashiro). He also contributed additional voices to classic dubs such as Kiki's Delivery Service and Castle in the Sky. In the realm of video games, Miller voiced the character Clasko in Final Fantasy X and its sequel, Final Fantasy X-2.

While voice acting forms a significant part of his career, Miller is also an accomplished stage actor and playwright. He has performed with the Royal National Theatre of Great Britain and served as the artistic director of the Sacramento Theatre Company starting in 2010. His experiences in anime voice acting directly inspired his one-man show, Fits & Starts: My Life in Stages, a memoir of his career. In recognition of his playwriting, he received the John Gassner Award in 2009 for his play Beat Aside Apollo's Arrow.