Indoor and outdoor home space may support physical activity (PA) and enhance motor skills (MS). However, there is limited knowledge about how indoor and outdoor home space affect PA and MS parent-child dyads. This cross-sectional study examined whether indoor and outdoor home spaces affect PA and MS in children and their parents. MS was measured with the Test of Gross Motor Development-3, and moderate to vigorous PA (MVPA) was assessed using accelerometry in 43 and 48 parent-child dyads, respectively. Indoor and outdoor home spaces were self-reported through an online questionnaire. Multiple regression models were fit to determine the relationship between indoor and outdoor home space and MS and MVPA in children and parents separately. Controlling for theory-based covariates, outdoor home space was positively associated with children's MVPA (p < 0.05) and parents' MS (p < 0.05) but negatively associated with parents' MVPA (p < 0.05). Indoor home space was negatively associated with parents' MS (p < 0.05). No other significant findings emerged. Findings suggest indoor and outdoor home spaces may play unique roles in supporting PA and MS among parent-child dyads and should be investigated in more rigorous studies.