Quality of life is widely acknowledged as one of the most important outcomes in autism research, but few measures of this construct have been validated for use in autistic people. The goal of the current study was to examine the psychometric properties of the Patient-Reported Outcomes Measurement Information System Global–10, an established self-report measure of health-related quality of life, in a sample of 901 autistic adults (predominantly female and adult-diagnosed) recruited from the Simons Foundation Powering Autism Research for Knowledge cohort. Using an item response theory framework, we performed a comprehensive psychometric evaluation of the Patient-Reported Outcomes Measurement Information System Global–10 in this sample, examining its latent structure, differential item functioning, reliability, and construct validity. After developing an autism-specific measurement model, the Patient-Reported Outcomes Measurement Information System Global–10 demonstrated excellent psychometric properties in the current sample, including excellent model-data fit, high reliability, minimal differential item functioning across subgroups of autistic adults, and an expected pattern of correlations with external variables. Exploratory analyses indicated that lower quality of life was associated with female sex and identified as a sexual/gender minority. A free online score calculator has been created to facilitate the use and interpretation of normed Patient-Reported Outcomes Measurement Information System Global–10 general quality of life latent trait scores for clinical and research applications (available at https://asdmeasures.shinyapps.io/promis_qol ). Lay Abstract Quality of Life an outcome that both researchers and autistic advocates agree is extremely important to consider when implementing services, interventions, and supports for autistic people. However, there has been little research on the topic of how quality of life can best be measured in autistic people or whether existing quality of life questionnaires are appropriate for use in the autistic population. This study aimed to validate an established quality of life measure, the Patient-Reported Outcomes Measurement Information System Global–10, in a large sample of autistic adults recruited online. We created a new way to score the Patient-Reported Outcomes Measurement Information System Global–10 scale and generate a “General quality of life” score specific to autistic adults. This new score performed very well in this sample, showing very little measurement error and relating in expected ways to similar constructs, such as physical health and emotional distress. Exploratory analyses found that lower quality of life was associated with female sex and self-identification as a sexual or gender minority (i.e. LGBTQ + identity). These findings suggest that the new Patient-Reported Outcomes Measurement Information System Global–10 quality of life score is a reliable and valid measure of quality of life in autistic adults, although additional studies are necessary to further explore its measurement properties in other subsets of the autistic population, such as individuals with intellectual disabilities. This measure is freely available for use as an outcome in both research and clinical practice, and an online score calculator is available to support the use of this measure in real-world applications.