Shinnosuke Mitsushima (満島 真之介, Mitsushima Shinnosuke, born May 30, 1989) is a Japanese actor. He graduated from Koza High School in Okinawa Prefecture. He is represented by Humanitè.

Mitsushima's older sister is former Folder and Folder 5 member and now actress Hikari Mitsushima. His younger sister is model Minami Mitsushima. Mitsushima's younger brother is Kotaro Mitsushima, a basketball player for the Rizing Zephyr Fukuoka of the Japanese Basketball League.

After graduating from high school, Mitsushima moved to Tokyo from Okinawa, worked there as an after-school care group counselor, and became the production director of the film Be Sure to Share.

After living in Tokyo for about two years, he took the opportunity and traveled around Japan by bicycle for seven months, from May to November 2009. Mitsushima traveled the country from Hokkaido to Kagoshima Prefecture. On the street, he saw posters, signs, and magazines for a film in which his older sister was appearing, and realized that his sister "impressed many people" and that he "also needed to work hard," and decided to devote himself to acting. Later, in December, Mitsushima joined the agency his sister was with.