Wilken Mazzei is a Brazilian actor and voice actor based in São Paulo. He began his acting career at the age of 13, working in theaters such as the Paulo Eiró and Cacilda Becker. He later received professional training at the Lee Strasberg Film & Theatre Institute in New York. Mazzei started his career in voice acting in 2012.

Mazzei is widely recognized for his role as the voice of Jotaro Kujo in the Brazilian Portuguese dub of the JoJo's Bizarre Adventure anime series. He voices the character across multiple parts, including Stardust Crusaders, Diamond is Unbreakable, Golden Wind, and Stone Ocean. He also voiced Gunpei Kamafusa and Mikitaka Hazekura in the Thus Spoke Kishibe Rohan OVA.

His other notable voice roles in anime include Kagaya Ubuyashiki in Demon Slayer: Kimetsu no Yaiba and its sequel film and arcs, Yohken Asakura in the 2021 Shaman King series, Edgeshot in My Hero Academia, and Han Kaioh in Baki. He also voices characters such as Saito in Ghost in the Shell: SAC_2045, Alexander Lloyds in Tiger & Bunny 2, Kaburagi in Deca-Dence, Josh/The Ghost in Super Crooks, Fatman in Spriggan, Ippeita Murao in Dance Dance Danseur, Sancho in Dragon Quest Your Story, Kouji Nagata in Back Street Girls: Gokudols, and Miche Zacharius in Attack on Titan: No Regrets.

In addition to his work as a voice actor, Mazzei has also served as an ADR director, including for the Portuguese-language version of the 2025 Ranma ½ television series.