This study utilized data from the Michigan component of the National Early Head Start Research and Evaluation study to examine toddlers' joint attention at 14 months (parent report measure of toddlers' initiating behaviors, e.g., extends arm to show you something he or she is holding, reaches out and gives you a toy he or she has been holding, and points at something interesting) as a mediator of the relations between early mother-child interactions (e.g., mother and child behaviors in response to one another's cues) and later school readiness skills in a low-income sample (N = 127 mother-child dyads). Understanding relations between early parent-child interactions, joint attention, and later school readiness skills is critical to identifying developmental paths of economically at-risk children. Results showed that toddlers' joint attention behaviors at 14 months partially mediated the path between mother-child interaction at 14 months and later school readiness, measured by children's emotion regulation, social-cognition, language development, and literacy and mathematics academic outcomes, at approximately 5 years of age. Results suggest the important roles of early mother--child interactions in low-income families and joint attention in promoting school readiness skills.