Mutsuki Iwanaka is a Japanese voice actor born on January 7, 1994, in Kitakyushu, Fukuoka Prefecture. He is affiliated with the talent agency Mausu Promotion, joining them on April 1, 2016, after completing his training at their associated training school in 2014.

Iwanaka began his professional career in 2015, taking on minor roles in series such as Aikatsu! and Bikini Warriors. The following year, he continued to build his experience with parts in Aikatsu Stars!, D.Gray-man Hallow, JoJo's Bizarre Adventure: Diamond Is Unbreakable, and Uta no Prince-sama. A significant early role was as Souji Kibino in both the Dream Festival! anime and its Data Carddass game.

The year 2017 proved to be pivotal for Iwanaka, landing him two notable recurring roles. He voiced Haruki Yamauchi in the first season of the popular series Classroom of the Elite and portrayed Daisuke Tachibana in the coming-of-age story Tsuki ga Kirei. That same year, he also took on the role of Mario Lotte in Vatican Miracle Examiner. He subsequently joined the cast of the long-running sports franchise Captain Tsubasa, providing the voice for Mamoru Izawa in the 2018 television anime and later reprising the role in the 2018 video game Captain Tsubasa ZERO: Miracle Shot. He continued in this role for the Captain Tsubasa: Junior Youth Arc.

In the following years, Iwanaka continued to secure a variety of roles. In 2023, he starred as Jay in the science fiction series The Gene of AI. The year 2024 saw him take on two significant lead roles: as Tsunehiro Sasaki, a university student given two years to live, in the original fishing anime Negative Positive Angler, and as Renji Aikawa in TsumaSho. He is also set to voice the character Banjirō Inumiya in the 2025 anime Chikuwa Senki ~Ore no Kawaii Chikyū Shinryaku~.

Beyond his work in anime, Iwanaka is active in video game voice acting, with credits including Souma Miyata in Hatsune Miku: Colorful Stage! and Ginga in Bar Stella Abyss. He also has an extensive career in dubbing foreign content into Japanese. Notably, he is the regular voice actor for South Korean actor Song Kang, dubbing his performances in dramas such as Sweet Home -俺と世界の絶望- and 恋するアプリ Love Alarm. He also provides the Japanese voice for the character Tyler Galpin in the series Wednesday and has voiced Spider-Man in the Japanese dub of the Marvel's Spider-Man animated series.

Iwanaka is known for his versatility, being a speaker of the Kitakyushu and Hakata dialects. His personal interests and special skills include hair styling, playing the nose flute, creating sound effects, and vocal mimicry.