Social support has a positive impact on quality of life (QoL) in neurotypical older adults and young autistic adults, but the association for older autistic adults is unclear. Autistic adults (n = 388; mean age = 40-83 years) were recruited via Simons Powering Autism Research for Knowledge (SPARK) Research Match. Participants completed questionnaires online querying demographic information, depression, and anxiety symptomatology, QoL (physical, psychological, social, environmental, and autism-specific) and social support (instrumental, subjective, and social interactions). Regression analyses examined whether different aspects of social support contributed to models explaining each domain of QoL. Models explaining QoL were significant. Subjective social support significantly contributed to the models for all aspects of QoL; social interactions contributed to the models for Physical and Psychological QoL, whereas instrumental support contributed to models for social, environmental and autism-specific QoL. Social support is an important contributor to the QoL of middle-aged and older autistic adults, after accounting for demographic factors and depression. Further studies are required to understand whether age-related changes in social support and QoL are the same for autistic as non-autistic older adults in order to identify and implement appropriate support.