Child obesity is a major public health issue with a high disease burden. Although numerous contributing factors have been identified, the family home environment is a central context of influence that requires deeper understanding. The level of organization in the family home environment may influence obesity and obesogenic behaviors, but the literature has suffered from the lack of a strong overarching construct and model to guide this area of research. Family entropy is a conceptual framework that fills this gap by representing the level of organization across the home environment. The current study empirically assesses family entropy using factor analysis in a longitudinal sample of 968 children measured yearly from Grades 3 to 6 as part of the NICHD Study of Early Child Care and Youth Development. Mixed modeling using MPLUS examined the influence of family entropy on child weight both directly and indirectly through weight-related health behaviors (i.e., sleep and physical activity), and considered the moderating role of socioeconomic status (SES). Results suggest that family entropy is comprised of distinct elements of household organization and disorganization, which are moderately related. Household disorganization may be particularly detrimental to child sleeping behavior both concurrently and over time in families of both high and low SES. The study concludes with recommendations for advancing understanding of the home environment by using nuanced measurement strategies, and incorporating support for household organization within child obesity prevention and intervention efforts.