Conceptualizing both economic well-being (EWB) and children's development as multidimensional constructs, the present study examines their association using bioecological developmental theory and structural equation modeling with Zulu children (ages 7-10) in KwaZulu-Natal, a highly impoverished region of South Africa (N = 1,958). Relative EWB within impoverished communities consists of three dimensions: material assets (durable goods and living environment), fiscal appraisal (subjective experiences of access to/allocation of resources), and fiscal capacity (monetary inflow/outflow). Children's development also is measured across multiple dimensions: physical health, mental health, and executive functioning. In addition to an overall association between EWB and children's development across outcomes, the sub-dimensions of EWB are differentially related to aspects of children's development. The dimension of material assets exhibits the greatest association with child outcomes, while fiscal capacity exhibits the least. Implications of these findings are discussed, including the use of multidimensional approaches to measuring EWB to understand, more clearly, its relationship to multiple dimensions of children's development. A video abstract of this article can be viewed at https://www.youtube.com/watch?v=ZcawZ6oOt-Q