Mariana Alexandre is a Brazilian actress, voice actress, singer, and musical theater performer. Born in Rio de Janeiro on March 6, 2001, she began her artistic journey at a young age, starting with music classes at six and transitioning to acting at twelve. Her career in voice acting includes a significant role as the Brazilian Portuguese voice of Azusa Aizawa, the protagonist of the anime series I've Been Killing Slimes for 300 Years and Maxed Out My Level, a part she has voiced since the show's first season and reprised for its second season in 2025. In the anime genre, she is also known for voicing Kikoru Shinomiya in Kaiju No. 8.

Beyond anime, Alexandre is widely recognized as the primary Brazilian dub voice for American actress Jenna Ortega, including the title role in the Netflix series Wednesday, a role she described as a dream come true, as well as in films like Beetlejuice Beetlejuice. Her extensive voice work spans numerous other productions for streaming platforms and television, including dubbing in series such as Cobra Kai, Sex Education, and Fate: The Winx Saga, as well as films like Annabelle: Creation. She has also lent her voice to animation, such as the character Rani in The Lion Guard.

In addition to her voice acting, Alexandre maintains an active career as an on-screen actress and singer. Her television roles include appearances in the Brazilian novelas Gênesis and Reis. In film, she has starred as the Brazilian rock icon Celly Campello in the biopic Um Broto Legal and appeared in Mallandro: O Errado Que Deu Certo. She is also a seasoned musical theater actress, with credits in major productions such as The Sound of Music, Mamma Mia!, and a Rock in Rio 40th-anniversary musical. A self-described "triathlete of the arts," she also composes her own music.