Masumi Kageyama is a Japanese voice actress and narrator affiliated with the agency Aoni Production. She was born on January 11 in Kyoto Prefecture. Kageyama is a graduate of Kyoto Notre Dame Women's University and is also a graduate of the 15th term of the Aoni Juku Osaka school, a training institution for voice actors.

Kageyama began her career in 1999. Since her debut, she has built a career by voicing a wide array of characters in anime, video games, and overseas film dubbing, as well as working extensively as a narrator. Her voice work is known for its warmth and versatility, and she often utilizes her native Kyoto and Kansai dialects in her performances.

Her career includes a substantial number of roles in television animation. She is recognized for playing supporting and recurring characters in many long-running and popular series. These include roles such as a classmate and a teacher in K-On!!, Maydee and the young Henzo in One Piece, and various characters in Chibi Maruko-chan. Other notable anime credits include Fullmetal Alchemist, Kanon, and Bobobo-bo Bo-bobo, where she voiced the character Risumi. She also voiced the character Ren'yū in the 2016 film Naze Ikiru: Rennyo Shōnin to Yoshizaki Enjō.

In addition to television and film, Kageyama has an extensive portfolio in original video animations and video games. Her OVA work includes the role of Choco in Gakuen Toshi Varanoir - Kingdom of Chaos The Universe and the role of Asuta in Hunter X Hunter: G I Final. In the realm of video games, she has voiced characters in major titles such as the Yakuza series, Persona 5 Royal, Shining Tears, and Riviera: The Promised Land. One of her prominent leading roles in a game is Saori Nonoka in Milky Season.

Beyond animation and games, Kageyama's work includes narration for television programs and documentaries, such as Therefore, I Live in Kyoto, and voice work for foreign film dubs. She has also been active in radio, hosting programs like Voice Sake Hannari.