The Platino Award for Best Supporting Actress (Spanish: Premio Platino a la mejor actriz de reparto/Premio Platino a la mejor interpretación femenina de reparto) is one of the Platino Awards, Ibero-America's film awards presented annually by the Entidad de Gestión de Derechos de los Productores Audiovisuales (EGEDA) and the Federación Iberoamericana de Productores Cinematográficos y Audiovisuales (FIPCA).
It was first presented in 2021, with Spanish actress Nathalie Poza being the first recipient, for her role as Violeta in Rosa's Wedding. Prior to that, supporting female performances were included in the Best Actress category.
No actress has won the award for than once. Conversely, Argentine actress Alejandra Flechner is the only actress to receive multiple nominations in the category, with two consecutive ones. As of 2025, all five winners have been Spanish actresses in Spanish productions.
In the list below the winner of the award for each year is shown first, followed by the other nominees.