Mariela Díaz is a Venezuelan voice actor known for her work in Latin American Spanish dubbing for anime, animated series, and live-action television. She is recognized for providing the voice for the title character in the anime series The Super Milk-chan Show. Her body of work in anime includes the role of Kenny in Beyblade V-Force and Beyblade G-Revolution. She also voiced Hotarubi in Basilisk, Kaoruko Kurushima in Hell Girl, and Sumika Kurita in an episode of Escuela de detectives. Díaz contributed additional voices for the anime series Solty Rei and Nodame Cantabile.

Beyond anime, Díaz has extensive credits in animated series, most notably in the Latin American dub of Winx Club. In that series, she voiced numerous characters across various seasons, including Zing, Ediltrude, Katy, Vanessa, Marion, Queen Niobe, Queen Ligea, and the pixie Ninfea, among many others. Her work also extends to live-action series; she voiced Betty in The Secret Life of the American Teenager, provided a guest voice for Sasha in an episode of Big Time Rush, and voiced Nicole Sullivan in an episode of Hollywood Medium with Tyler Henry.