Nicolas Mattos is a Brazilian voice actor known for his work in the dubbing of various anime series for the Brazilian Portuguese market. He is recognized for voicing young male characters and has been active in the industry, contributing to several high-profile anime titles.

Mattos has built a notable portfolio with several major voice roles in popular anime series. He is the Brazilian Portuguese voice of Ewen Egeburg, a classmate of Damian Desmond and friend to Emile Elman, in the hit series Spy×Family, a role he also reprised for the feature film Spy×Family Code: White. He voices the young Sōta Hori, the younger brother of the protagonist, in the romantic comedy Horimiya. In the supernatural series Kemono Jihen, he provides the voice for the character Nobimaru. He also voices the titular character, a young boy trying to live independently, in the series Kotaro Lives Alone.

Beyond these roles, his voice work extends to other significant anime. He has voiced a younger version of Zeke Jaeger in Attack on Titan The Final Season and a young Wakana Gojō in My Dress-Up Darling. His other credits include roles in Moriarty the Patriot, The Faraway Paladin, and the young Dot Barrett in Mashle: Magic and Muscles, among others. He is also noted to be the brother of fellow Brazilian voice actress Nicole Mattos, and they have both appeared in the same projects, such as the dubbing of Kemono Jihen where Nicole voiced the character Aya. His body of work demonstrates a consistent presence in the Brazilian dubbing industry, particularly in voicing child and adolescent characters across a wide range of anime genres.