Children from racial minority and low socioeconomic (SES) households are at greatest risk for overweight and obesity (OWOB) and sleep is a risk factor. Although most research linking sleep and OWOB has focused on sleep duration, emerging evidence indicates that additional aspects of sleep (i.e., day-to-day variability in sleep) are independently associated with greater adiposity, poor emotional regulation, and lower quality of life in children. Sleep variability is not well understood in children due to cross-sectional study design, and parent- or self-reported sleep data. Current research is only beginning to examine the multifaceted nature of sleep, but a better understanding of sleep variability through longitudinal designs is needed to identify health implications. Further, the home environment is a major contributor to children’s sleep, yet few studies have examined the this beyond a single facet (i.e., bedtime routines). Home disorganization (e.g., chaos, noise) is associated with poor physical and mental health. Children from low SES families may be more likely to experience home disorganization compared to peers from high SES families. Of the studies examining the relationship between home environment and sleep in elementary school-age children, many included predominately white, affluent samples. One of these studies sampled children from low SES households and used an objective measure of sleep. Understanding home disorganization and its relationship to sleep, beyond duration, among children from minority and low SES households holds promise for identifying salient intervention targets to improve sleep, which can lead to improved weight status and reduce health disparities. This project leverages data collected from a longitudinal cohort (N = 504) of 1st - 3rd grade children from low and high SES households, with a 50% African American sample (NIDDK:R01DK116665) and a RCT (N = 140) of 1st - 3rd grade children from low SES households (NIDDK:R01DK120490) randomized to attend summer camp. Home disorganization is assessed via questionnaires and daily diaries for 14 days during the school year and summer. Simultaneously, children’s sleep is objectively assessed with wrist-based accelerometry. The primary aim will determine the moderating effects of SES and race/ethnicity in the association between home disorganization and sleep variability. The secondary aim will identify differences in home disorganization between the school year and summer, and their relationship with sleep variability. The home environment and intraindividual sleep variability are emerging factors associated with the risk of OWOB yet are understudied components of children’s obesogenic behaviors. This study is significant as greater understanding of home environment and insight into potential intervention targets will be possible. This study is innovative as it utilizes a longitudinal and RCT design, employs an objective measure of sleep, and assesses home disorganization...