Objective: To examine the moderating effects of subjective sleep quality (SSQ) and sleep duration on the relationships between mindfulness and health behaviors (i.e. nutrition and exercise) among undergraduate students. The unique influence of the five facets (i.e. factors) of mindfulness (i.e. observing, describing, acting with awareness, nonreactivity to inner experience and nonjudging of inner experience) on students' health behaviors was also explored. Participants: Three hundred fifty seven undergraduate students enrolled in U.S. colleges. Methods: Students completed an online survey. Hierarchical multiple regression analyses were conducted to determine whether SSQ moderated the relationship between mindfulness and nutrition behavior. Results: SSQ moderated the relationship between mindfulness and nutrition behavior. The observe facet of mindfulness was the most predictive of nutrition behavior, whereas the observe and describe facets were the most predictive of exercise behavior. Conclusions: Interventions that target mindfulness and sleep quality may help promote healthy eating and increased exercise engagement in college students.