Objective: The objective of this article was to provide an overview of the development and recommendations from the Australian evidence-based clinical practice guideline for attention deficit hyperactivity disorder (ADHD). The guideline aims to promote accurate and timely identification and diagnosis, and optimal and consistent treatment of ADHD. Methods: Development integrated the best available evidence with multidisciplinary clinical expertise and the preferences of those with lived experience, underpinned by the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. The 23 guideline development group members included psychiatrists, paediatricians, general practitioners, psychologists, speech pathologists, occupational therapists, educators, Indigenous psychologists, and people with a lived experience; with two independent chairs and a methodologist. Where appropriate, evidence reviews from the National Institute for Health and Care Excellence (NICE) 2018 ‘Attention Deficit Hyperactivity Disorder: Diagnosis and Management’ guideline were updated. Fifty prioritised clinical questions were addressed in 14 systematic reviews (new and updated from NICE 2018) and 28 narrative reviews. Results: The 113 clinical recommendations apply to young children (5 years and under), children, adolescents and adults. They provide guidance for clinicians on identification, screening, diagnosis, multimodal treatment and support, including pharmacological and non-pharmacological interventions. The guideline and supporting information are available online: https://adhdguideline.aadpa.com.au/ Conclusions: The guideline was approved by the National Health and Medical Research Council (NHMRC) of Australia and relevant medical and allied health professional associations. It is anticipated that successful implementation and uptake of the guideline by organisations, health care providers and other professionals will increase delivery of evidence-based treatment and improve health outcomes for the more than 800,000 Australians with ADHD.