Marianna Vianna Alexandre is a Brazilian actress, voice actor, and singer, born in Rio de Janeiro on March 6, 2001. Her artistic journey began in childhood with music, participating in choirs and learning piano from the age of six. She later studied at the Escola de Música de Brasília and was invited to audition for a film in 2013, which led to her first role in the movie O Outro Lado do Paraíso. Her introduction to theater came at the age of twelve, and she has since performed in musical productions such as A Noviça Rebelde and Mamma Mia.

Alexandre's career in voice acting began in August 2016. Her early projects included dubbing Margaret Hodgson in the film The Conjuring 2 and Amelia Silva Pato in the Disney series Bizaardvark. In the realm of animation and anime, she voiced the character Rani in the series The Lion Guard. In the anime Eden, she provided the Portuguese voice for the character Zurich. A significant milestone in her dubbing career was being cast as the voice of Wednesday Addams, played by Jenna Ortega, in the Netflix series Wednesday. This role brought her widespread recognition and was a personal dream project for her. Her association with Jenna Ortega continued in other films, including The Fallout and Beetlejuice Beetlejuice.

Beyond these roles, Alexandre's voice work spans a variety of live-action and animated productions. She has dubbed characters in series such as Cobra Kai, Sex Education, and Fate: The Winx Saga. Her film dubbing credits include Cindy in Spider-Man: Homecoming. She has also voiced Gabby Duran in Gabby Duran & the Unsittables and Flora in Fate: The Winx Saga. In addition to her dubbing work, Marianna Alexandre has built a concurrent career as an on-screen actress. She stars as Amarilis in the television series Gênesis, a role for which she won the Prêmio Contigo! Online for Revelation of the Year in 2021. She also appeared as Merit in the series Reis and portrayed Brazilian singer Celly Campello in the film Um Broto Legal. Alexandre is also a singer and a prominent social media personality, amassing millions of followers on platforms like TikTok.