Masashi Tamaki is a Japanese voice actor from Niigata Prefecture. While sources offer conflicting information regarding his birth date, with some indicating September 5, 1985, and others September 5, 1989, his professional activities in the industry are well-documented. He is affiliated with the talent agency Accent. Prior to his voice acting career, Tamaki demonstrated proficiency in kendo and sword dancing, holding a second-degree rank in the former.

Tamaki is perhaps best known for his role as the rival prosecutor Miles Edgeworth, known in Japanese as Reiji Mitsurugi, in the anime adaptation of the Ace Attorney video game series. He first voiced the character in the 2016 anime Ace Attorney and reprised the role for its second season, Ace Attorney Season 2, which aired in 2018. This performance stands as one of his most significant and recurring roles in anime.

His work in anime also includes the role of Ruu in the series Uchū Nanchara Kotetsu-kun. He voiced this character in both the first season of the show in 2021 and its second season in 2022. Additionally, he had a role in the long-running franchise Pretty Cure, appearing in Hug! Pretty Cure in 2018.

Beyond anime series, Tamaki has an extensive portfolio in video game voice acting. His notable game credits include providing the voice for the antagonist Zant in both Hyrule Warriors and its enhanced version, Hyrule Warriors Legends. He has also contributed to major game releases such as Nioh and Tactics Ogre: Reborn, and is set to appear in the 2025 title Assassin's Creed Shadows.