Genomic technologies have accelerated research progress in autism spectrum disorder (ASD) genomics and promises to further transform our understanding of the genetic basis of this neurodevelopmental disorder. Here we review the current evidence for the genetic basis of ASD, present the progress of large-scale studies to date and highlight the potential of genomic technologies. In particular, we discuss evidence for the importance of identifying rare genetic variants in family-based studies. Genomics is a key feature of future healthcare and our review illustrates it's potential to improve our biological understanding of neurodevelopmental disorders, and to ultimately aid ASD diagnosis, inform medical decision making and establish genomics as central to personalised medicine.