Ryūnosuke Kamiki is a Japanese actor and voice actor born on May 19, 1993, in Saitama Prefecture, Japan. He is a graduate of Horikoshi High School. His career in entertainment began at the age of two when his mother enrolled him in a talent agency, leading to early work in commercials and television dramas. He made his official acting debut in 1999 with a role in the television series Good News.

Kamiki's voice acting career was launched through his collaboration with Studio Ghibli. In 2001, his expressive voice caught the attention of director Hayao Miyazaki, leading to his first voice role as the baby Boh in the Academy Award-winning film Spirited Away. He continued his relationship with Ghibli by voicing Markl, the young apprentice, in Howl's Moving Castle and later as Sho in The Secret World of Arrietty.

One of the most significant milestones in his voice acting career came in 2016 when he voiced the male lead, Taki Tachibana, in Makoto Shinkai's blockbuster animated film your name. His performance in this role earned him the Lead Actor Award at the 11th Seiyu Awards. His other notable lead voice roles in animated films include Kenji Koiso in Summer Wars, Shuuhei Amamiya in The Piano Forest, and Peter in Mary and The Witch's Flower. He also voiced the character of the Crocodile in the film 100 Nichikan Ikita Wani.

Beyond animation, Kamiki has portrayed a wide range of characters in live-action film and television, which are also integral to his career profile. He played the role of Sōjirō Seta in the live-action Rurouni Kenshin film series and Kōichi Hirose in the live-action adaptation of JoJo's Bizarre Adventure: Diamond Is Unbreakable. He also starred as the protagonist Rei Kiriyama in the live-action film adaptations of March comes in like a lion and played Akito Takagi in the film adaptation of Bakuman.. In 2023, he starred in the live-action film Godzilla Minus One.

Throughout his career, Kamiki has been recognized for his acting talent with several awards. He won the Newcomer Award at the 29th Japan Academy Film Prize for his first leading role in the film The Great Yokai War. He also received the Best Supporting Actor award at the 77th Drama Academy Awards for his performance in the television series Family Game. He was a child actor known for being the inspiration for several anime characters, including the protagonist of the manga The Catcher and the character Nona in the Ghibli short film The Day I Bought a Star. Until 2021, he was represented by the agency Amuse, after which he transferred to the newly established company Co-LaVo.