The purpose of this review was to identify the quantity, breadth, and methodological characteristics of literature examining parent perspectives of autism spectrum disorder diagnosis, synthesize key research findings, and highlight gaps in the current literature. A systematic search was conducted for the period January 1994–February 2020. One hundred and twenty-two articles underwent data extraction. The majority of studies took place in Europe and North America in high-income countries. Over half of the studies used qualitative methodology. Four key components of the diagnostic experience were identified: journey to assessment, assessment process, delivery of the diagnosis and feedback session, and provision of information, resources, and support. Themes of parental emotions and parental satisfaction with the diagnostic process were also found.