Background: Little is known about the friendships and relationships of autistic adults, despite decades of research evidence showing the benefits of close relationships for neurotypical adults. Even less is known about the relationships of autistic women, or how their relationships compare to those of neurotypical women. This mixed-methods study therefore examined differences in the social relationships of autistic women in relation to their neurotypical counterparts. Methods: Thirty-eight women (19 autistic women, 19 neurotypical women), aged between 20 and 40 years, completed the Unidimensional Relationship Closeness Scale (URCS), The Awareness of Social Inference Test (TASIT), and a semi-structured interview about their current and former friendships and romantic relationships. Results: In many ways, the social relationships and experiences of autistic women were much like those of neurotypical women. Autistic women, however, had greater difficulty with social inference skills, and reported experiencing more negative social situations. This was particularly the case in terms of social and sexual vulnerability, a feature that the autistic women themselves linked to their difficulties with social inference. Despite these challenges, autistic women were happier and more self-assured in their adult relationships than they remembered being in adolescence. Conclusions: These findings highlight an urgent need for specific and tailored personal safety training and support for autistic womenand, by extension, autistic girlsto ensure that they can enjoy a safe transition to adulthood and positive adult relationships.