Pepa Castro is a Spanish voice actress with a lengthy career in dubbing, primarily known for providing Spanish voices for numerous actresses and characters in films, television series, and animation. Based in Madrid, she began her career in the 1980s, entering the world of dubbing after being inspired by her aunt, fellow voice actress María Pe Castro. Over more than four decades, she has become a well-established figure in the Spanish dubbing industry.

Castro is recognized for being the regular Spanish dubbing voice for several prominent actresses, including Jennifer Aniston, Kim Cattrall, and Kyra Sedgwick. Her extensive voice work spans a wide variety of genres. In live-action, some of her notable roles include Samantha Jones in Sex and the World (for Kim Cattrall) and Cersei Lannister in Game of Thrones (for Lena Headey). Her work also extends to video games and, significantly, to the dubbing of animated and anime productions for the Spanish market.

Within the realm of anime and animation, Castro's filmography is extensive. She voiced the role of Tenar in the Studio Ghibli film Tales from Earthsea. In another Ghibli production, she took on the part of the witch Bella Yaga in Earwig and the Witch. Her work in the Pokémon franchise is particularly notable; she voiced the antagonist Oakley in the film Pokémon Heroes - Latias & Latios. She has also portrayed other characters in the Pokémon universe, such as the villainous Pokémon Hunter J in Pokémon Diamond & Pearl, and additional roles in Pokémon Advance and the original series. Other prominent anime credits include Lady Eboshi in Princess Mononoke, Paninya in Fullmetal Alchemist, Flora in Carole & Tuesday, and Nicolás Téllez in A Dog of Flanders. Her work is not limited to Japanese animation; she has also dubbed roles in live-action adaptations of anime and other international productions, such as Rachel in the Sonic the Hedgehog live-action films.