Tomoyuki Dan was a Japanese actor and voice actor born on August 6, 1963, in Osaka Prefecture. His birth name was Yoshio Tanaka. He pursued acting after dropping out of Kwansei Gakuin University, where he had planned to study economics. He graduated from the Seinenza Acting Studio's 11th class and joined the Seinenza Theater Company in April 1987, which remained his primary professional affiliation for his entire career. While stage acting was his foundation, he built a prolific career in television, anime, and voice dubbing for foreign films.

Dan's anime career included a wide range of roles, often voicing characters with a distinctive and unique voice. One of his earliest regular roles was as Cronicle Asher in the 1993 series Mobile Suit Victory Gundam. He is perhaps best known internationally for his work as the recurring villain Kisame Hoshigaki in the long-running Naruto and Naruto: Shippuden anime series, a role he played from 2004 until his passing. Other notable anime credits include Sasha in Planetes (2003), Masaya Orihara in Air Gear (2006), and Ishikawa in Ghost in the Shell: Arise (2013). He also took on roles in popular franchises such as Suite PreCure, where he voiced Dan Hōjō in 2011, and Detective Conan, to which he contributed the voices of numerous characters across many episodes. In 2013, he voiced the character Rohm in the short anime film A Farewell to Weapons, part of the Short Peace anthology.

Beyond anime, Dan was highly active as a dubbing artist, becoming the regular Japanese voice for Hollywood actors Christian Bale and Ben Stiller. His dubbing credits for Christian Bale included Batman in Batman Begins, The Dark Knight, and The Dark Knight Rises, as well as John Connor in Terminator Salvation. For Ben Stiller, he provided voices in films such as Night at the Museum and its sequel, and Along Came Polly. He also dubbed performances for actors like Brad Pitt in Snatch, Tim Roth in The Incredible Hulk, and James Marsden as Cyclops in the X-Men film trilogy.

In live-action, Dan is well-remembered for his role as the villainous Doctor Shinkuro Isaka, also known as the Weather Dopant, in the popular tokusatsu series Kamen Rider W in 2009, a role for which he provided both his likeness and voice. He also appeared in numerous Japanese television dramas and films throughout his career.

Tomoyuki Dan was married to fellow actress and voice actress Ryoko Gi. His career was cut short when he died on October 10, 2013, at the age of 50, due to a relapse of an aortic dissection at his home in Tokyo. Following his death, several of his roles in ongoing series and dubbing works were taken over by other voice actors, ensuring the characters he helped define continued on.