Sleep-disordered breathing is an underrecognized comorbidity in the cystic fibrosis (CF) population across the lifespan. Nocturnal hypoxia, obstructive sleep apnea (OSA), and nocturnal hypoventilation are respiratory abnormalities that occur commonly during sleep, and have deleterious consequences to quality of life in people with CF. Effective screening for these abnormalities is needed to allow for the timely initiation of treatment. Lack of treatment leads to worse pulmonary, cardiovascular, and metabolic outcomes in patients. In this review, we give an overview of sleep-disordered breathing for the CF clinician, including definitions, treatment, and suggestions for future research. We strongly encourage the CF community to incorporate evaluation for sleep-disordered breathing, so that outcomes for the subset of the patients with coexisting sleep-disordered breathing improve.