Mario Arenas is a Spanish voice actor known for his work in dubbing anime series and films for Spanish audiences. He has been active in the dubbing industry since at least the mid-1990s, with a career that extends into live-action dubbing and documentaries as well.

Arenas is most recognized for his extensive contributions to the various Spanish dubs of the Sailor Moon franchise. He has voiced multiple characters across several series and films. Notably, he provided the Spanish voice for Artemis, the white cat companion of Sailor Venus, in numerous productions, including the original Sailor Moon, Sailor Moon R, Sailor Moon S, Sailor Moon SuperS, and the film Pretty Guardian Sailor Moon Eternal. Additionally, he took on the role of Mamoru Chiba, also known as Tuxedo Mask, the male lead and partner of Sailor Moon, in several installments of the franchise, including Sailor Moon S, Sailor Moon SuperS, and Pretty Guardian Sailor Moon Eternal. His other roles within the Sailor Moon universe include characters such as Camilo Umino, Ramiro (Nephrite), and Prince Demand.

Beyond Sailor Moon, Arenas's anime dubbing credits include significant roles in other popular series and films. He voiced the character González in Captain Tsubasa: Road to 2002 and portrayed the villain Lawrence III in the Spanish dub of Pokémon 2000 - The Movie. He also provided the voice for Meowth in Pokémon 3 - The Movie and the special Pokémon: Mewtwo Returns.

His professional career encompasses a wide range of dubbing work for various productions, demonstrating his versatility as a voice actor.