Rikiya Koyama is a prominent Japanese actor and voice actor born on December 18, 1963, in Kyoto Prefecture, Japan. He is affiliated with the Haiyuza Theatre Company. Koyama stands 173 cm tall and has blood type O. His journey into performance began after he graduated from Ritsumeikan University, where he studied law. He then pursued his interest in drama at the Toho Gakuen College of Drama and Music before joining the Haiyuza Theatre Company.

Koyama's career started on the stage as a theatrical actor, and he made his on-screen acting debut in the tokusatsu series Kamen Rider Black RX in 1989, performing many of his own stunts. He transitioned into voice acting in the mid-1990s, initially focusing on dubbing foreign films and TV series. His voice became widely recognized in Japan as the primary dub-over artist for several major Hollywood actors, including George Clooney, Kiefer Sutherland, and Dwayne Johnson. His role as Jack Bauer in the Japanese dub of the series 24 is considered one of his most famous dubbing performances.

From the 2000s onwards, Koyama became increasingly active in anime and video games, establishing himself as a leading voice actor known for portraying a wide range of characters. He is particularly renowned for roles that require a deep, powerful, and charismatic voice, often playing authoritative figures, stoic heroes, or formidable villains. Some of his most iconic anime roles include Mamoru Takamura in Hajime no Ippo, Hakuoro in Utawarerumono, Kiritsugu Emiya in the Fate series, Klaus Von Reinhertz in Blood Blockade Battlefront, and Yamato in Naruto Shippuden. In 2009, he took over the role of Kogoro Mouri in the long-running series Detective Conan, succeeding the previous voice actor, and has voiced the character ever since, becoming a defining role in his career.

Throughout his extensive career, Koyama has demonstrated remarkable versatility. He has voiced characters ranging from the comedic Tora in Ushio and Tora to the villainous Sea King in One Punch Man, and from the charismatic Yukichi Fukuzawa in Bungo Stray Dogs to the ruthless Kagetane Hiruko in Black Bullet. His work also extends to video games, with notable roles such as Sun Wukong in the Warriors Orochi series and Duke in Tales of Vesperia.

His contributions to the voice acting industry have been recognized with awards. In 2001, he received the Outstanding Performance Award at the 9th Yomiuri Theater Awards for his stage performance as Antonio in The Merchant of Venice. In 2011, he was honored with the Kei Tomiyama Memorial Award at the 5th Seiyu Awards, which recognizes a voice actor for their significant body of work and contributions to the industry. Rikiya Koyama continues to be an active and highly sought-after talent, with ongoing and upcoming roles in major anime franchises like Detective Conan and Demon Slayer, solidifying his legacy as one of Japan's most distinguished voice actors.