We examined the potential mediating roles of domain-specific physical activities and sedentary behaviors in the relationship between area-level socioeconomic status (SES) and cardiometabolic risk.Data were from the 2011/2012 Australian Diabetes, Obesity and Lifestyle study (n = 3431). The outcome was a clustered cardiometabolic risk (CCR) score, and the exposure was suburb-level SES. Potential mediators were domain-specific physical activities and sedentary behaviors. Multilevel linear regression models examined associations between SES and potential mediators (α) and between mediators and CCR (β). Mediation was assessed using the joint-significance test.Higher SES was associated with a lower CCR score. Lower SES was associated with less frequent walking for transport, lower vigorous-intensity recreational physical activity, and higher TV time, which were associated with higher CCR scores. However, higher SES was associated with longer transport-related sitting time (all modes and in cars), which were associated with higher CCR scores.The SES-cardiometabolic risk relationship may be partially explained by walking for transport, vigorous-intensity recreational physical activity, and TV viewing. These findings, which require corroboration from prospective evidence and clarification of the roles of transport-related sitting and occupational physical activity, can inform initiatives addressing socioeconomic inequalities in cardiometabolic health.