A child’s early language environment is pivotal for language development. Disparities in the early language environment contribute to the gap in school readiness between poor and more advantaged children, and ultimately to disparities in students’ school achievement and economic outcomes. While recent research has highlighted the value of early intervention for children in disadvantaged families, most existing interventions begin too late, reach only a small proportion of children at risk, and do not capitalize on the critical role that parent language plays in a child's educational trajectory. To address this challenge, we propose to develop and evaluate a novel language-based, perinatal public health intervention, Thirty Million Words Newborn Public Health Initiative (TMW-NI), that new mothers will receive while their babies are undergoing the universal newborn hearing screen. The intervention will use video, animation, and interactive questions to convey the importance of the early language environment and to illustrate strategies parents can use to promote language learning. We will conduct formative research with mothers of low socioeconomic status (low-SES) and with healthcare providers to inform the content and format of the intervention. Also critical for acceptability, we will use an iterative approach to develop the intervention, with review of the work-in-progress by the intended audience. To assess feasibility and initial efficacy, we will conduct a randomized-controlled trial with low-SES mothers during the newborn period. We hypothesize that TMW-NI will positively impact parents’ knowledge and beliefs about the role of their own language input for their child’s language development.