Autistic girls and women experience more mental health difficulties and poorer well-being than their non-autistic peers. Little emphasis has been placed on the perspectives of the girls and women within the literature. This review aims to provide an overview of the factors that impact autistic females' emotional and social well-being and mental health, as described in self-report qualitative studies. The protocol for the present review was pre-registered on PROSPERO (CRD42020184983), and this article follows Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PsycInfo, Academic Search Complete and MEDLINE were systematically searched using a pre-defined search string. This yielded 877 unique records, which were systematically screened by two reviewers, resulting in 52 eligible studies. Structured data extraction and quality appraisal were completed. The present review presents the perspectives of 973 autistic females aged 13-70+. Thematic synthesis identified three themes and nine subthemes. Our findings suggest that autistic girls' and women's experiences can be conceptualised within a social model, where biological and psychological factors ("The Autistic Neurotype") are experienced through the lens of social factors ("The Neurotypical World" and "Stigma"), together shaping well-being and mental health outcomes.