Kimiko Furuyama is a Japanese voice actress and singer who performs under the professional name Kimiko Koyama. She was born on January 27, 1979, in Tokushima City, Tokushima Prefecture, Japan. Her career began after she passed a voice acting audition while still in high school, leading to her debut role as Pirol in the 1997 series Coji-Coji shortly after graduation.

Koyama is known for a voice often described as cute, high-pitched, and energetic, which has made her a frequent choice for youthful and lively characters. One of her early and defining roles is Uzuki Shiten'nou in the Happy Lesson franchise, which included an original video animation, a television series, and the sequel Happy Lesson Advanced, as well as the final OVA, Happy Lesson The Final. Her portfolio of notable anime roles includes Komoe Tsukuyomi in A Certain Magical Index and its sequels and spin-offs, Fuka Narutaki in various adaptations of Negima! Magister Negi Magi, Yukari Sendo in Rosario + Vampire, Mao Onigawara in Ground Defense Force! Mao-chan, and Pepe in the Shugo Chara! series.

Beyond her extensive anime work, Koyama has voiced characters in video games such as the title role in YU-NO: A Girl Who Chants Love at the Bound of this World. She is also a singer who has released solo music and participated in numerous character songs. She was a member of the voice actress unit Pastel during its original run from 2003 to 2004 and again following its revival in 2016. In a unique career development, Koyama enrolled in the NSC Tokyo School for Comedians in 2009. For nearly two years, she performed as a solo comedian under the name Kimikimi while continuing her voice acting work, a rare combination of professions in the Japanese entertainment industry.