Terumi Niki is a Japanese actress and voice actress born in Tokyo on May 11, 1949. Her career in entertainment began at a very young age when she debuted as a child actor in 1955. She gained significant critical recognition at sixteen years old for her performance in Akira Kurosawa's 1965 film Red Beard, for which she received the Blue Ribbon Award for Best Supporting Actress, becoming the youngest person to win that award at the time.

In addition to her extensive work in live-action film and television, Niki built a notable career as a voice actor in anime, particularly active during the 1970s. One of her prominent early voice roles was as the heroine Simone Lorrain in the 1975 television anime series La Seine no Hoshi. The following year, in 1976, she voiced the character Youko Misaki in the super robot series Gowapper 5 Godam, a role of particular note as Youko was one of the first female leaders in a super robot anime. Niki also contributed her voice to the popular Lupin III series, making a guest appearance in the second television series where she voiced Oscar, the protagonist of The Rose of Versailles, for a special 100th episode celebration.

Niki's filmography also includes multiple voice roles in the Ganbare!! Tabuchi-kun!! series of comedy films based on the baseball manga. She voiced the character Miyoko Tabuchi in the first film released in 1979, as well as in its sequels, Gekitō Pennant Race and Ā Tsuppari Jinsei. Later in her career, she took on the role of Tae Okajima in the acclaimed 1991 Studio Ghibli film Only Yesterday. Beyond performing, Niki has also worked as a lecturer teaching drama at St. Margaret's Junior College.