IntroductionFetal alcohol spectrum disorder (FASD) is one of the most common neurodevelopmental disorders in North America. It is a complex disability, associated with challenges in cognitive, behavioural and socialemotional functioning, as well as an increased risk of physical and mental health comorbidities, and difficulties in daily living across the lifespan. Previous attempts to characterise the profile of this population have been hampered by differences in data collected across studies, regional discrepancies in terminology and definitions, and a lack of tools to integrate comprehensive datasets.Methods and analysisThe goals of this study are to use the Canadian National FASD Database, a national repository of FASD assessment-related information, to better understand the functional profile, comorbidities, intervention needs and difficulties in daily living experienced by individuals assessed for FASD across the lifespan. We will also examine what factors may be the most sensitive predictors of receiving an FASD diagnosis. Data will be analysed from over 3500 records collected between 2010 and 2021 (ongoing) from 26 FASD diagnostic clinics in seven provinces and territories. Data collection is ongoing, and analysis will be performed on a biannual basis to continue to hone our understanding of the profiles, needs and outcomes of individuals assessed for FASD in Canada. This research is critical for refining FASD assessment and diagnostic practice, enabling accurate and early identification of individuals with FASD, and connecting individuals with FASD and their families to comprehensive and effective services and resources to support healthy developmental trajectories.Ethics and disseminationEthics approval for the National FASD Database Project was obtained from the Ottawa Health Science Network Research Ethics Board. As new knowledge is gained from this project, findings will be disseminated through publications, presentations and feedback to participating clinics, with the ultimate goal of informing FASD research, practice and policy.