We examined whether parental happiness associate with preschoolers’ healthy energy balance-related behaviors (EBRBs) and with the co-occurrence of multiple healthy EBRBs. This cross-sectional study included 647 pairs of parents (88% mothers) and children (mean age 4.7, SD 0.9 years). Parents completed the Subjective Happiness Scale. In addition, ActiGraph accelerometers measured children’s physical activity, and parents reported screen time and food consumption on behalf of their children. We defined four healthy EBRBs: meeting physical activity guidelines; meeting screen time guidelines; a higher consumption of vegetables, fruits and berries; and a lower consumption of sugary foods, treats and drinks. Parental happiness scores did not associate with children’s healthy EBRBs when each behavior was analyzed separately. However, parents with higher happiness scores were more likely to have a child with 2 or 3–4 healthy EBRBs than a child with 0–1 healthy EBRBs. To conclude, parents who are happier have children with multiple healthy EBRBs. Targeting parental wellbeing should be considered when promoting children’s healthy EBRBs.