Structural equation models were used to examine pathways from maternal depression and early parenting to children's executive function (EF) and externalizing behaviours in the first nationally representative study to obtain direct assessments of children's kindergarten EF skills (i.e., the Early Childhood Longitudinal Study Kindergarten Class of 2010–2011). Preliminary analyses revealed that maternal depression was negatively related to children's EF and positively related to children's externalizing behaviour problems. However, the negative association between maternal depression and children's EF was completely mediated by maternal parenting practices (i.e., warmth and home learning stimulation). Furthermore, there was an indirect effect from maternal parenting practices to children's externalizing behaviour problems through EF, such that children with stronger EF skills had fewer externalizing behaviour problems. Findings provide support for a family process model in which warm, cognitively stimulating parenting supports children's EF, which in turn decreases externalizing behaviours. Highlights This study examined pathways from parent mental health to children's executive function (EF) and behaviour problems. Maternal depression was negatively related to children's EF and positively related to children's behaviour problems. The negative association between maternal depression and children's EF was completely mediated by maternal parenting. There was an indirect effect from maternal parenting to children's behaviour problems through EF.