Satoshi Niwa is a Japanese voice actor affiliated with the agency Atomic Monkey. Born on March 11 in Kanagawa Prefecture, he began his career in the early 2020s after graduating from the Atomic Monkey Voice Actor & Acting Research Institute as part of its 13th generation.

Niwa's early work consisted primarily of supporting and background roles in notable series. His first credited television appearance was in 2021 voicing a character in the series Bottom-Tier Character Tomozaki, with additional early work including roles in 86 Eighty-Six, More Than a Married Couple, But Not Lovers, and The Dreaming Boy is a Realist. The year 2024 marked a significant turning point in his career when he was cast in his first leading role as Kōta Shimura, also known as Yoo Hobin, in the anime adaptation of Viral Hit (Kenka Dokugaku). This performance brought him widespread recognition and praise from established figures in the voice acting industry.

Beyond his breakthrough role, Satoshi Niwa has built a diverse filmography. He portrays Shūji Nihonyanagi in the series Tasūketsu -Fate of the Majority-. He is also part of the Japanese voice cast for the Netflix anime series Leviathan, where he plays the character Matthews. Other anime roles include Haraol in Helck, Marcus Kischa in As a Reincarnated Aristocrat, I'll Use My Appraisal Skill to Rise in the World, and a student in the film Blue Thermal. His voice work extends to video games as well, including roles in the popular mobile game Monster Strike.

In addition to his on-screen work, Niwa has been active in other media. He has served as an assistant on the streaming program atomic7, where he formed a trio known as Shingōzu with fellow voice actors Yoshihide Itō and Takuya Yokota. He has also appeared on stage in theatrical productions and hosted a monthly segment on a national radio program, demonstrating his versatility as a performer.