Sixto Pondal Ríos (April 8, 1907 - September 29, 1968) was an Argentine screenwriter, poet and dramatist.
Rios was born in San Miguel de Tucumán, Argentina. Although most of his film work took place in Argentina, the 1948 film Romance on the High Seas was based on his story (with Carlos Olivari) and is notable as Doris Day's first film role. He died in Buenos Aires, aged 61.