Mark Okita is an Australian-born Japanese actor, voice actor, and narrator best known for providing the equipment voices for several transformation devices in the Kamen Rider franchise. Born on November 10, 1969, in Sydney, Australia, he holds both Australian and Japanese nationality. Okita spent his middle and high school years in England and the United States before later attending Gakushuin University. He is affiliated with the talent agency Osawa Office.

Okita’s most iconic role is the voice of the Decade Driver, the transformation belt for the protagonist of the 2009 series Kamen Rider Decade. He also voiced the accompanying Diendriver, K-Touch, and provided the tournament announcer voice for the Rider Battle in the film Kamen Rider Decade: All Riders vs. Dai-Shocker. His association with the character continued in later productions, including Kamen Rider Zi-O, where he voiced the Neo Decadriver and Neo Diendriver, as well as the K-Touch 21 in Rider Time: Kamen Rider Decade VS Zi-O. He later returned to the franchise to voice the Legendriver and Legend Kamen Riser in Kamen Rider Gotchard. Beyond the television series, Okita has reprised these device voices in numerous Kamen Rider films, including Cho Kamen Rider Den-O & Decade Neo Generations: The Onigashima Warship, Kamen Rider × Kamen Rider Double & Decade: Movie War 2010, Heisei Rider vs. Shōwa Rider: Kamen Rider Taisen feat. Super Sentai, and Kamen Rider × Super Sentai: Super Hero Taisen.

Outside of tokusatsu, Okita has worked extensively as a narrator and voice actor in anime. He voiced a computer announcer in the film Tiger & Bunny the Movie: The Beginning and served as the narrator for the anime series Future Card Buddyfight and Future Card Buddyfight 100. In video games, he provided the voice of the announcer for KOF: Maximum Impact 2 and Regulation A. His commercial narration work includes campaigns for major brands such as McDonald's, Volkswagen, Lipovitan, Samsung, Snickers, and Listerine. He has also worked as a narrator for Japanese television programs like Run for Money (Tousouchuu) and Battle For Money (Sentouchuu). In a more recent anime role, he provided the voice for the Amen Buckle in Sentai Red Isekai Boukensha de Naru. As an on-screen actor, Okita made an appearance in the Hollywood film The Last Samurai.

Okita has collaborated directly with Masahiro Inoue, the actor who portrayed Tsukasa Kadoya (Kamen Rider Decade), on promotional material for the Complete Selection Modification (CSM) Decadriver toy in 2014, where he recorded new sound lines for the high-end collectible item. He continued recording new voice lines for subsequent releases, including the CSM Diendriver and an updated version of the CSM Decadriver in 2022.