This study uses the bioecological framework and methodology to select items for and to test a multidimensional structure of a measure of children’s economic well-being in a multi-community sample of children (7–11 years) and their households (N = 1958) from KwaZulu-Natal, a poor and under-served region of South Africa. Economic well-being was assessed using questionnaires completed by children’s caregivers and household heads. Exploratory factor analysis of four random split halves identified three dimensions of economic well-being: Fiscal Appraisal (subjective experiences of access to/allocation of resources), Material Assets (durable goods and living environment), and Fiscal Capacity (traditional measures of poverty: income, expenditures, employment). Confirmatory factor analysis verified the higher order model of economic well-being with the three dimensions. Invariance testing using multiple group factor analysis indicated confidence for use of this measure with varying types of communities in South Africa. The results reflect the multidimensional nature of economic well-being. Thus, the often-used money metric measures of poverty likely paint an incomplete picture of children’s actual economic well-being. Because our sample consists of impoverished households, our measure of economic well-being is sensitive to variation at the deep end of poverty. Implications for theory and future research are discussed.