Susumu Terajima is a Japanese actor primarily known for his extensive work in live-action film and television, with a limited number of voice acting credits to his name. He was born on November 12, 1963, in Tokyo. His interest in acting began in his youth, and he pursued this path by enrolling at the Mifune Art Academy after high school. Terajima made his acting debut in 1986 with a minor role in the film A Homansu.

His career is most notably defined by his long-standing collaboration with filmmaker Takeshi Kitano. He played a supporting role in Kitano's Violent Cop in 1989, which marked the beginning of their professional relationship. Terajima's breakthrough performance came with Kitano's 1993 film Sonatine. He has since become a familiar face in Kitano's works, often portraying yakuza figures, a role for which he is particularly well-known. Beyond his work with Kitano, Terajima has built a prolific career with over a hundred film and television roles, frequently appearing in supporting parts. He has worked with acclaimed directors such as Hirokazu Kore-eda in films like After Life (1998), Air Doll (2009), and Still Walking (2008).

While his filmography is dominated by live-action performances, Terajima has occasionally contributed his voice to animated projects. His most prominent voice role is in the Studio Ghibli film When Marnie Was There (2014), where he voiced the character Kiyomasa Ōiwa. He also provided a voice for the anime film Steamboy (2004), playing the character Alfred Smith. In the realm of video games, he lent his voice to the character Ito Ittosai in the 2008 game Ryu ga Gotoku Kenzan!, a spin-off of the Yakuza series. He also reprised his live-action role as the character Jiro Kawara for the video game Yakuza Kiwami 2.

Throughout his career, Terajima has built a reputation for his serious approach to acting, regardless of the size of his role. His long-term associations include frequent work not only with Takeshi Kitano but also with fellow actor Ren Osugi. His contributions to Japanese cinema are extensive, making him a well-respected and recognizable figure in the industry.