The experience of stigma by autistic people is relatively understudied, despite contributing to a range of poor outcomes and having an overarching impact on wellbeing. The current review of the literature synthesises research to determine what is currently known and presents a theoretical model of autism stigma. Autism stigma is primarily influenced by public and professional understanding of autism in combination with interpretation of visible autistic traits. Moderating factors include the quality and quantity of contact with autistic people, cultural factors, sex and gender, individual differences, and diagnostic disclosure. Stigma can reduce wellbeing as well as increase the presence of camouflaging behaviours, which mask autistic traits. Caregivers of autistic people can experience stigma by association, i.e. affiliate stigma, which can impact their own wellbeing. A variety of interventions and approaches to reduce stigma are discussed, including 'autism friendly' spaces, positive media representation, educational and psychosocial training for the public and professionals, as well as cultural and systemic shifts that foster inclusivity and recognise neurodiversity.