AbstractObjective:The present study examines the association between mild and moderate-to-severe household food insecurity and school readiness among a nationally representative sample of preschool-aged children.Design:Cross-sectional data pertaining to household food availability as well as four domains of school readiness – early learning skills, self-regulation, social-emotional development and physical health & motor development – were employed.Setting:The USA.Participants:15 402 children aged 3–5 years from the 2016–2018 National Survey of Children’s Health.Results:Both mild and moderate-to-severe food insecurity are associated with an increase in needing support or being at-risk in each of the four school readiness domains, particularly Self-Regulation (IRR = 4·31; CI 2·68, 6·95) and Social-Emotional Development (IRR = 3·43; CI 2·16, 5·45). Furthermore, while nearly half of the children in food-secure households are on-track across all four school readiness domains (47·49 %), only one in four children experiencing moderate-to-severe household food insecurity is on-track across all domains (25·26 %).Conclusions:Household food insecurity is associated with reductions in school readiness among preschool-aged children.