Kazushige Nagashima is a Japanese actor and former professional baseball player who was born on January 26, 1966 in Tokyo, Japan. While he maintains a career across film and television, his work as a voice actor includes a notable role in an acclaimed animated feature film.

Nagashima provided the voice for the character Koichi in Hayao Miyazaki's Academy Award-nominated animated film Ponyo, which was released in 2008. In this capacity, he contributed to a major production by Studio Ghibli, one of Japan's most celebrated animation studios.

While Nagashima appears in the. Nobuhiko Komyoji and in the 2002 live-action drama You're Under Arrest as Ken Nakajima, these are live-action performances rather than voice acting roles. In the case of the You're Under Arrest franchise, the anime adaptation features a different actor providing the voice for the same character.

His acting credits span several television series and films, including the 2002 series Mr. Rookie and the 2005 film Yamato. For his performance in Mr. Rookie, Nagashima received the Best Newcomer award at the 26th Japan Academy Film Prize in 2003, as well as the Best Newcomer Award from the Hochi Film Awards in 2002.