Kenji Mizuhashi is a Japanese actor and voice actor born in Tokyo on January 13, 1975. He is affiliated with the talent agency Stardust Promotion. Mizuhashi has built a career primarily as a live-action film and television actor, appearing in numerous projects since the late 1990s. His early film roles include appearances in horror films such as Tomie in 1998 and Kairo in 2001. His work in live-action cinema includes a lead role in the 1999 film Moonlight Whispers.

In the realm of anime, Mizuhashi is best known for his sole leading voice role as Takaki Toono in Makoto Shinkai's 2007 film 5 Centimeters Per Second. His casting for this part came about through director Makoto Shinkai's specific admiration for his work. Shinkai had seen Mizuhashi in the live-action film Moonlight Whispers and was particularly impressed by his voice. When casting for 5 Centimeters Per Second, Shinkai felt Mizuhashi's vocal quality, which possessed both high and low registers, was perfectly suited to portray the protagonist Takaki from elementary school through to adulthood, leading him to cast Mizuhashi as the sole voice for the character across his life stages.

Beyond this iconic role, Mizuhashi's other voice acting credits are limited. He is credited with a voice role in the 2008 anime television series The Diary of a Cautious Magician (also known as Magician's Academy), though his role was a minor one. His filmography is otherwise overwhelmingly composed of live-action performances. His extensive live-action credits include appearances in the 2008 film The Taste of Tea, a 2008 guest role in the tokusatsu series Kamen Rider Kiva, a role in the 2016 taiga drama Sanada Maru, and a part in the 2020 live-action drama The Way of the Househusband. He also appeared in the 2023 film Godzilla Minus One.