Obstructive sleep apnoea occurs in 1-3% of children, but up to 60% with obesity. The mechanisms of OSA in obesity will be reviewed and the importance of screening for OSA in children with obesity will be highlighted. A brief discussion of screening tools including oximetry will be presented, with an outline of referral pathways and investigation of OSA. Lastly, treatment modalities for OSA and the challenges of treatment in this cohort will be discussed.