Bilingualism changes how people relate to others, and lead their lives. This is particularly relevant in autism, where social interaction presents challenges. Understanding the overlap between the social variations of bilingualism and autism could unveil new ways to support autistic people. This research aims to understand the language learning and social experiences of mono-, bi- and multilingual autistic people. A total of 297 autistic adults (mean age = 32.4 years) completed an online questionnaire including general demographic, language history and social life quality self-rating items. The sample included 89 monolingual English speakers, 98 bilinguals, and 110 multilinguals, with a wide range of language profiles. Regression models were used to analyse how bilingualism variables predicted social life quality ratings. In the full sample, age negatively predicted social life quality scores while the number of languages known positively predicted social life quality scores. In the multilingual subset, age negatively predicted social life quality scores, while third language proficiency positively predicted social life quality scores. This is the first study describing the language history and social experiences of a substantial sample of bilingual and multilingual autistic adults. It provides valuable insight into how autistic people can learn and use a new language, and how their bilingualism experiences shape their social life. Lay abstract Bilingualism changes the way people relate to others. This is particularly interesting in the case of autism, where social interaction presents many challenges. A better understanding of the overlap between the social variations of bilingualism and autism could unveil new ways to support the social experiences of autistic people. This research aims to understand the language learning and social experiences of autistic people who speak one, two or more languages. A total of 297 autistic adults (aged between 16 and 80 years) completed an online questionnaire that included general demographic questions, social life quality self-rating questions, language history questions, and open questions about the respondents’ bilingualism experience. Respondents had a wide range of language experiences: there were 89 monolingual English speakers, 98 bilinguals, 110 respondents knew three languages or more, all with a wide range of abilities in their languages. In the full group, younger respondents were more satisfied with their social life, and respondents with many languages were more satisfied with their social life than respondents with few languages. In the multilingual group, younger respondents were more satisfied with their social life, and the more skilled in their third language the more satisfied with their social life. This is the first study describing the language history and social experiences of a large group of bilingual and multilingual autistic adults. It highlights how autistic people can encounter a new language, learn it and use it in their daily life, and how their bilingualism experiences shape their social life.