IntroductionAutism spectrum disorder (ASD) is one of the national mental health priorities that has manifested a wide variability in practice in the Kingdom of Saudi Arabia (KSA). This work aimed to adapt evidence‐based clinical practice guidelines (CPGs) for ASD to synthesize the first national CPG for the management of children with ASD in KSA.MethodsThe CPG adaptation group comprised multidisciplinary expert clinicians and a CPG methodologist following the KSU‑Modified‑ADAPTE methodology. The last search date for source evidence‐based guidelines was March 2022.RecommendationsThree main categories of recommendations were included: (i) prevention and early identification, coding, psychometric tools, telehealth, risk factors and referral criteria, (ii) diagnosis, differential diagnosis, investigations and family support, (iii) interventions with problem minimization and avoidance, treatment goals, physical wellbeing, nonpharmacological interventions, sensory integration, parent‐mediated interventions, cognitive behavioural therapy, pharmacological interventions, psycho‐education of the family, special cases or comorbidities, sleep management, gastrointestinal and feeding interventions, the transition of care from paediatrics to adulthood. CPG implementation tools included a baseline assessment tool, clinical scenarios, pathways, quality measures, referral forms, screening tools and useful online resources. The adapted CPG presents practical, evidence‑based guidance with implementation tools for managing children with ASD in KSA. The project illustrated the applicability of the KSU‑modified‑ADAPTE and highlighted the importance of collaboration between clinicians and methodologists for adapting national CPGs.