Mário Santos is a Portuguese voice actor known primarily for his long-standing work on the European Portuguese dubs of various animated series and films, most notably the Pokémon anime franchise. His career in dubbing spans several decades, with credits dating back to the early 1990s.

Santos's most prominent and enduring role is providing the voice of Meowth, the talking Pokémon from Team Rocket. He has been the voice of Meowth since the eleventh season of the anime and in all Pokémon movies starting from the tenth, making him the most tenured voice for the character in Portugal. In addition to Meowth, Santos is also the regular narrator for the Pokémon series and films, a dual role he has performed consistently for many years. His filmography within the franchise includes major titles such as Pokémon the Movie: Volcanion and the Mechanical Marvel, Mewtwo Strikes Back Evolution, Pokémon the Movie: Diancie and the Cocoon of Destruction, and many others where he voices both Meowth and the narrator. He has also voiced other characters in the Pokémon world, such as the rival Paul in the Diamond and Pearl series and Champion Alder in Black and White: Rival Destinies.

Beyond Pokémon, Santos has a prolific career with a wide range of voice roles. His work includes voicing Alvin and Dave in the Portuguese dubs of the Alvin and the Chipmunks film series, Musculoso in Regular Show, Diretor Nigel Brown in O Incrível Mundo de Gumball, and Kaos in Academia Skylander. He has also contributed to dubs of popular live-action series, such as providing the voice of Derek Hale in Teen Wolf and Valentine Morgenstern in Shadowhunters. His extensive body of work demonstrates his versatility and long-standing presence in the Portuguese dubbing industry.