Kaori Shimizu is a Japanese voice actress and actress from Tokyo, born on May 21, 1983. She began her entertainment career in the first grade, appearing in television commercials and dramas as a child actor. Her voice acting debut came in 1998 when she was in junior high school, providing the voice for the titular character in the experimental series Serial Experiments Lain. She is affiliated with the talent agency Three Tree.

Shimizu has built a extensive career with a wide variety of roles in anime, video games, and OVAs. Some of her most notable and long-running parts include the knight Signum in the Magical Girl Lyrical Nanoha franchise, a role she has reprised across multiple television series, movies, and games starting from Nanoha A's in 2005. She is also known for her work in long-running series such as Noriko Nijō in Maria Watches Over Us, Akira Takano in School Rumble, and Hiyori Tamura in Lucky Star. In the early 2000s, she played lead roles in distinctive titles like Boogiepop Phantom and the film A.LI.CE.

Throughout her career, Shimizu has frequently collaborated with specific production teams and franchises. She has a long association with the Super Robot Wars franchise, voicing the character Lamia Loveless in various animated adaptations and games. She has also taken on roles in several mystery and puzzle-solving anime, such as Nonoha Itō in Phi Brain: Puzzle of God. Beyond anime, her work extends to video game voice acting, with roles in major titles like Tales of Hearts and the Japanese dub of BioShock, where she voiced the Little Sisters. Her career has remained active into the 2020s, with roles in new projects such as the 2025 anime Cultural Exchange with a Game Centre Girl.