Research Findings: Using data from 3,250 participants in the Early Childhood Longitudinal Study, Birth Cohort, we used structural equation modeling to investigate whether family routines (e.g., bedtime routine, reading routine) established in preschool predict children's school readiness (i.e., academic skills, social-emotional skills, and physical health) in kindergarten, a foundational year for establishing children's academic trajectories. Analyses revealed that higher levels of routines in preschool were associated with greater declines in teacher-reported conduct problems and hyperactive/inattentive behavior and greater gains in prosocial behaviors from preschool to kindergarten. Higher routines also predicted greater gains in both reading and mathematics scores as well as greater improvements in physical health. Telling stories appears to be the most salient routine for children's social-emotional outcomes, whereas bedtime routines most strongly predicts differences in children's academic skills and health outcomes. Practice or Policy: The results suggest that family routines may be an important tool for preparing and supporting children and parents for the kindergarten transition even before school entry. (author abstract)