Much research about child poverty and disadvantage provides national estimates of child wellbeing, due to the ready availability of microdata at the national level. However, an increasing body of evidence suggests that there can be major differences in wellbeing between children living in different geographic areas. In addition, much recent debate has focussed on moving beyond income poverty to broader measures of social exclusion. This article describes the development of a composite index of child social exclusion risk for Australian small areas, using 2006 Australian Bureau of Statistics Census data, and building on earlier work based on 2001 Census data. Variables included in the index are based on characteristics of children’s parents, families and households, and include data about parental partnership status, employment and volunteerism, family educational attainment and occupation, household income, housing, transport and internet connection. Results show that there are pronounced spatial differences in the risk of child social exclusion, with areas of high social exclusion risk common in Australia’s rural and regional balance, and in clusters of outer areas in most of Australia’s capital cities.