Anxiety is the most common co-occurring condition in children on the autism spectrum but the potential impacts of anxiety on social and academic outcomes of children on the autism spectrum have not been systematically examined. In this review, 50 studies were identified that explore the relationship between anxiety and scores on social or academic measures in children on the autism spectrum. Social competence was frequently measured, and the findings of these studies were mixed. While other social constructs have received little attention, associations were found between anxiety and victimisation, and anxiety and social relationships. Only three studies focused on the impact of anxiety on scores on academic measures, highlighting the need for further research in this area. Anxiety was most frequently measured using subscales from broader behavioural instruments, which may not capture the range of anxiety symptoms of children on the autism spectrum. Future studies that include multi-informant methodologies and proportional representation of females and children with intellectual disability will further knowledge of the impact of anxiety in children on the spectrum.