Background: Shortened sleep duration is associated with poor health and obesity among young children. Little is known about relationships among nighttime sleep duration, sleep behaviors, and obesogenic behaviors/obesity among toddlers. This study characterizes sleep behaviors/duration and examines relationships with obesogenic behaviors/obesity among toddlers from low-income families., Methods: Mothers of toddlers (age 12-32 months) were recruited from urban/suburban sites serving low-income families. Mothers provided demographic information and completed the Brief Infant Sleep Questionnaire (BISQ); a 6-item Toddler Sleep Behavior Scale was derived (TSBS-BISQ, higher score reflects more recommended behaviors). Toddler weight/length were measured; obesity defined as ≥95th percentile weight-for-length. Measures of obesogenic behaviors: physical activity [accelerometry, minutes/day in Moderate-to-Vigorous Physical Activity (MVPA)] and diet quality [24-hour recall, Healthy Eating Index 2005 (HEI-2005)]. Bivariate and adjusted multivariable models examined associations between nighttime sleep behaviors/duration and obesogenic behaviors/obesity., Results: Sample included 240 toddlers (mean age = 20.2 months), 55% male, 69% black, 59% urban. Toddlers spent 55.4 minutes/day in MVPA, mean HEI-2005 score was 55.4, 13% were obese. Mean sleep duration was 9.1 hours, with 35% endorsing 5-6 recommended sleep behaviors (TSBS-BISQ). In multivariable models, MVPA was positively related to sleep duration; obese toddlers had a shorter nighttime sleep duration than healthy weight toddlers [odds ratio = 0.69, p = 0.014]. Nighttime sleep duration was associated with high TSBS-BISQ scores, F = 6.1, p = 0.003., Conclusions: Toddlers with a shorter nighttime sleep duration are at higher risk for obesity and inactivity. Interventions to promote healthy sleep behaviors among toddlers from low-income families may improve nighttime sleep duration and reduce obesogenic behaviors/obesity., Competing Interests: Author Disclosure Statement No competing financial interests exist.