Most U.S. preschoolers have consumed media created with funding from the U.S. Department of Education's Ready To Learn (RTL) initiative, which was established to promote school readiness among children ages 2-8. Synthesizing data from 45 evaluations (N = 24,624 unique child participants), this meta-analysis examined the effects of RTL media exposure on young children's literacy skills. Results indicate positive effects of RTL media exposure on children's literacy outcomes, especially vocabulary and phonological concepts. These effects are equivalent to about one-and-a-half months of literacy learning above and beyond typical growth. Findings are robust across a variety of research designs and for exposure to both television and new media. These results are discussed in terms of accountability evidence for RTL and larger debates in scholarly understanding of educational media effects.