This study investigates whether a curriculum supplement organized as a sequence of teacher-led literacy activities using digital content from public educational television programs can improve early literacy outcomes of low-income preschoolers. The study sample was 436 children in 80 preschool classrooms in California and New York. Preschool teachers were randomly assigned to implement either a 10-week media-rich early literacy intervention that employed clips from "Sesame Street", "Between the Lions", and "SuperWhy!" or to a comparison condition. The media-rich literacy supplement had positive impacts (+0.20 less than or equal to d less than or equal to +0.55) on children's ability to recognize letters, sounds of letters and initial sounds of words, and children's concepts of story and print. The study findings show the potential for incorporating literacy content from public media programming into curriculum supplements supported by professional development to impact early literacy outcomes of low-income children. (Contains 4 tables.)