This review aimed to identify the post-graduation training pathways available for both clinicians and trainers in the assessment and diagnosis of Autism Spectrum Disorder (ASD). The study was guided by two research questions: What is known about ASD-specific educational, training, or other pathways available to support clinicians of any discipline, post-graduation, to meet the required expertise relevant to assessments of ASD concerns? What is known about the educational pathways available to clinicians seeking to provide training to other clinicians, post-graduation, in the assessment of ASD concerns? A scoping review was undertaken with searches completed across five databases (PubMed, PsycINFO, PsycEXTRA, ERIC and CINAHL). A Google search strategy was also executed using the "advanced" search function. Eligible records were literature, written in English, that examined post-graduation training and/ or education of clinicians to assess and/ or diagnose ASD. Fourteen relevant records were identified. Post-graduate training has the potential to enhance clinician confidence and service provision in ASD assessment and diagnosis. System-wide training approaches show promise in building large-scale, diagnostic capacity and the use of tele-mentoring offers a cost-effective, convenient mode of training delivery. A lack of evidence to support ASD diagnostic training pathways was found and may pose a challenge for clinicians and service users. The limited evidence found suggests that high quality research will be fundamental in determining how to build clinician capacity in ASD assessment and diagnosis and to ascertain whether training pathways are a necessary component.