Autism spectrum disorder (ASD) is a neurodevelopmental condition marked by communication and social challenges, and repetitive behaviors. Early integrated developmental and behavioral interventions are recommended, ideally during peak brain development at ages 2-4. Sleep problems are common in autistic children and may appear before diagnosis. This narrative review, informed by a systematic literature search, examines how sleep disturbances affect neurodevelopment in young children with ASD and whether treatment of sleep problems may enhance response to developmental intervention. We conducted a systematic literature search on developmental trajectories AND autism AND/OR intervention AND/OR sleep (Scopus, PubMed, Scholar, Jan 2015-Jan 2026) with focus on early development and intervention (age 2-5 years) in children with ASD. Sleep is essential for brain development, learning, memory, and emotional regulation. Insufficient sleep hinders intellectual growth and adaptive skills, reducing the effectiveness of speech, language, and behavioral interventions. Extending sleep-through behavioral strategies or medications like prolonged-release melatonin-can improve educational outcomes and adaptive behavior in young children with ASD. Addressing sleep issues promptly when ASD is diagnosed or suspected may improve developmental outcomes and enhance intervention effectiveness.