Seiji Fukushi is a Japanese actor and voice actor born on June 3, 1983, in Kanagawa Prefecture, Japan. He began his entertainment career in 2001 when he appeared in a commercial, making his drama debut the following year in 2002. He is affiliated with the agency OWLM.

While primarily known as a screen actor in television dramas and films, Fukushi has also taken on several voice acting roles throughout his career. Among his notable voice credits is the role of Yūma Shiobara in the live-action series The Next Generation -Patlabor-, which is based on the classic anime and manga franchise. He portrayed the character Yasunori Kuroki in the live-action adaptations of Nodame Cantabile, including the Fuji Television drama series and the subsequent two-part finale film, Nodame Cantabile: The Final Movement. His role as Akio Nitta, the genius batter and rival in the live-action film adaptation of the beloved baseball manga Touch, also features prominently in his filmography.

Beyond these roles, Fukushi has provided his voice for the animated series Yamishibai: Japanese Ghost Stories (also known as Dark Theater) in its second season, where he voiced characters including Takuya's father and Shimazaki Shinji. His broader acting career includes a breakout role in the 2006 NHK morning drama Junjo Kirari and a lead role in the NHK period series Otokomae!. He has demonstrated versatility across genres, appearing in the acclaimed mystery drama Unnatural, the comedy film Swing Girls, and forming the rock unit MISSION in 2019 to pursue what he describes as Theater Rock.