PurposeSleep disturbances are prevalent in autistic children. The emergence of telehealth offers new possibilities for remote professional intervention. By combining telehealth with parental support, this study aims to explore a novel family-based model to enhance moderate-to-vigorous physical activity (MVPA) and improve sleep quality in children with autism.MethodsThirty-four autistic children (mean age = 15.7 years) were randomly assigned to either a 6-month intervention group or a control group. Both groups received standard physical education classes at school. The intervention group received additional after-school telehealth support. MVPA and sleep quality were assessed 1 week before the intervention and at the 6-month follow-up.ResultsAfter 6 months, children in the intervention group nearly doubled their daily MVPA compared to the control group (Cohen's d = 8.34, CI95% = 6.17–10.52). Actigraphy-assessed sleep efficiency was notably higher (d = 2.35, CI95% = 1.44–3.26), and there were reductions in wake time (d = 1.65, CI95% = 0.84–2.46), sleep fragmentation (d = 0.80, CI95% = 0.07–1.52), and sleep latency (d = 0.82, CI95% = 0.09–1.54) were all reduced. These improvements in objective sleep metrics were corroborated by subjective assessments using the Sleep Disturbance Scale for Children (d = 0.86, CI95% = 0.13–1.59).ConclusionsTelehealth combined with parental support addresses barriers to enhancing health behaviors at home. This innovative model not only improves after-school MVPA and sleep quality in autistic children but also holds significant potential for benefiting other populations requiring remote support.Clinical Trial Registrationhttps://clinicaltrials.gov/study/NCT06444659?id=NCT06444659&rank=1 (NCT06444659).