Introduction: Resilience is a process that develops as a complex transaction as children experience and shape their social-ecological contexts. The dynamic development of self-regulation is an aspect of resilience that has received increased attention as a key mechanism predicting a variety of important short-and long-term outcomes. The current study examined how the self-regulation skills of infants and toddlers in a classroom could potentially shape classroom interactions and quality which, in turn, could potentially shape the development of self-regulation skills of the individual infants and toddlers enrolled in the classroom across an early childhood program year. The unique contribution of this study is the focus on a critical component of resilience, self-regulation, in an understudied age group, infants and toddlers, in an important and understudied context, the infant-toddler early childhood classroom. Methods: Data are from a statewide evaluation of early childhood programs serving children birth to age 3 growing up in low-income contexts. Multi-level mediation models were employed to examine the mediation effect of classroom quality between classroom-level self-regulation and individual children’s gain in self-regulation over a year. Results: We found a significant indirect path. The results showed that classroom-level self-regulation skills demonstrated by infants and toddlers in the fall predicted higher levels of teachers’ implementation of three important aspects of classroom quality – support for social-emotional, cognitive, and language development – in the winter. We also found that higher levels of teachers’ support for social-emotional, cognitive, and language development associated with children’s increased growth in self-regulation skills from fall to spring. The direct path from classroom-level self-regulation demonstrated in the fall to individual children’s gain in self-regulation was not significant. (author abstract)