Routines in the family are a potential source of resilience for at-risk children and support children's emerging emotion regulation. Meanwhile, inadequate sleep has been linked with deficits in cognitive processes to attend to environmental stimuli and with poor emotion regulation for children. The detrimental effects of poor sleep are potentially worse in low-income children. The aim of the current study was to examine the moderating role of sleep in the association between family routines and emotion regulation in toddlers in poverty. We analyzed data of 130 toddlers (24-31 months; 58% boys) from low-income, primarily African American families. Mothers completed questionnaires about child routines (Child Routines Questionnaire; CRQ; Wittig, 2005).To measure emotion regulation, toddlers completed an observed behavioral task meant to elicit frustration (Lab-TAB-Locomotor Version; Goldsmith & Rothbart, 1991). As hypothesized, adequate sleep (> 11 hr) fully moderated the association between routines and observed emotion regulation. There was no effect of routines on emotion regulation for toddlers with inadequate amounts of sleep. Analyses controlled for toddler respiratory sinus arrhythmia (RSA) as well as maternal emotion dysregulation (the Emotional Dysregulation Scale; EDS; Westen, Muderrisoglu, Fowler, Shedler, & Koren, 1997). These results emphasize the importance of sufficient sleep in at-risk toddlers. Furthermore, the results suggest that the effectiveness of family interventions focusing on family health to increase toddler emotion regulation could be improved by incorporating sleep interventions/routines. (PsycINFO Database Record (c) 2018 APA, all rights reserved).