Mariela Álvarez is an Argentine voice actress born in Buenos Aires on February 22, 1978. She is recognized for her work in the Latin American dubbing industry, contributing her voice to a variety of characters in anime, television series, and films.

Her career in anime dubbing includes several notable roles. She provided the Spanish voice for the character Julie or Juri in the cyberpunk series Serial Experiments Lain. In the Sonic X anime, she voiced Amy Rose for a specific set of episodes, from episode 53 to 78. She is also known for her role as Ben Miyanoshita, also known as Keiichirou, in the anime series Ghost Stories.

Beyond her work in anime, Álvarez has an extensive filmography in other areas of voice acting. She voiced the character Jessie in the Pokémon film Jirachi Wish Maker. In the world of live-action series adaptations, she lent her voice to Elsa, also known as Mrs. Randall, in Power Rangers Dino Thunder and to Cornelia Hale in the animated series W.I.T.C.H.. Her work also extends to dubbing for films such as High School Musical, where she voiced Taylor McKessie.