Children’s early life experiences are important not only for their contemporary wellbeing, but also for their subsequent life outcomes as adolescents and adults. Research from developed countries has demonstrated that children in one-parent and reconstituted families have worse socio-emotional and behavioural functioning than children from ‘normative’ or ‘intact’ families. We use recent Australian data from a nationally representative birth cohort study to examine the associations between family structure and children’s socio-emotional and behavioural outcomes. We contribute to the literature in two ways: by testing whether previously established relationships in the US and the UK apply in Australia, and by deploying an innovative life course methodological approach that pays attention to the accumulation, patterning and timing of exposures to different family types during childhood. As in other countries, children in Australia who spend time in one-parent or reconstituted families experience more socio-emotional and behavioural problems than other children. Such differences disappear when accounting for socio-economic capital and maternal mental health. This suggests that providing additional income and mental health support to parents in vulnerable families may contribute to mitigating children’s socio-emotional and behavioural difficulties in Australia.