Sleep is essential for health and daily functioning, and social relationships may be a key social factor influencing sleep, yet sleep has been understudied in the literature on social relationships and health. This study used data from the National Survey of Midlife Development in the United States to examine associations between troubled sleep and family contact, social support, and strain. Results show that having strained family relationships is associated with more troubled sleep, while supportive family relationships are associated with less troubled sleep. Family strain is more consequential for sleep than support, and sleep troubles are greatest when family relationships are highly strained and provide inadequate emotional support. Family strain is also more harmful to sleep among individuals who are in frequent contact with family members. These findings underscore the importance of focusing on both negative and positive aspects of relationships and highlight the significance of family relationships for sleep.