To characterize the relationship between positive early childhood experiences (PECEs) and school readiness, and assess whether the PECEs-school readiness relationship was robust to and/or differed across levels of adverse childhood experiences (ACEs). We analyzed national data on children ages 3-5 from 2016 to 2020 (n=26 871) to examine associations between key PECE domains (nurturing relationships, home learning opportunities, safe and stable environments, and family routines) with being on track for school readiness, defined using a pilot, multidimensional measure called "healthy and ready to learn". Weighted univariate, bivariate, and multivariable analyses were conducted to generate nationally representative estimates. Multivariable models adjusted for sociodemographic factors and were assessed both with and without cumulative ACE exposure. Two-fifths of children were healthy and ready to learn. Exposure to PECEs was associated with higher school readiness, irrespective of relative ACE exposure. Compared with those with low PECEs, children with moderate (aOR, 2.19; 95% CI, 1.86-2.58) and high (aOR, 4.37; 95% CI, 3.58-5.34) PECEs had greater odds for being healthy and ready to learn, net of both sociodemographic factors and ACE exposure. Significant associations were robust across demographic groups (eg, race and ethnicity), ACE levels, and ACE types (eg, parental incarceration). Increasing PECEs correspond with greater likelihood of possessing capacities key for school functioning, even amidst ACEs. In concert with efforts to ameliorate early life trauma, caregivers, health care providers, educators, and systems can consider boosting PECEs to foster healthy development in childhood and beyond.