Purpose of review <p>To summarize existing evidence of associations between religion and spirituality in relation to multiple dimensions of sleep health, illuminate strengths and limitations of the existing literature, and outline gaps that inform opportunities for future research.</p> Recent findings <p>Positive dimensions of religion and spirituality, such as spiritual well-being, supportive coping, and community integration, were generally associated with better sleep outcomes across global populations. Adverse experiences, including doubt, conflict, and spiritual struggle, were often associated with poorer sleep. Among the 59 included studies, most were cross-sectional and relied on self-reported measures, used inconsistent conceptualizations of religion and spirituality, did not sufficiently assess potentially adverse religious or spiritual experiences, and were limited to certain geographic regions of the world (e.g., North America and Southwest Asia).</p> Summary <p>Positive dimensions of religion and spirituality (e.g., meaning, coping) were generally associated with better sleep, while struggles and doubt were associated with poorer sleep. Future research that employs longitudinal and experimental designs, validated multidimensional measures, objective sleep assessments, and diverse populations is needed to clarify mechanisms and inform culturally responsive approaches to promoting sleep health.</p>