Background: At least 25% of autistic children worldwide have the potential to grow up in a bilingual environment. However, many autistic children are being denied opportunities to access additional languages and the cultural, familial and community connections that come with this. There is little evidence identifying the barriers to language learning and access, and no research addressing the perspectives of speech and language therapists (SLTs), who are crucial in supporting parents to make informed choices about bilingualism with their child. Aims: The aim of this research was to understand the experiences of SLTs working with autistic bilingual children, to understand the main considerations when working with families, and the opportunities and barriers for training, including the sources of information that current practice is based on. Methods and Procedures: Twelve SLTs from across the United Kingdom were recruited for this study. All participants were experienced in working with autistic bilingual children and their families (M = 7 years, range 4-23 years). Semi-structured interviews were conducted and focused on the experiences of SLTs regarding familial bilingual experiences, the effect of sociocultural factors of practice, and the extent to which practice is based on current research. Outcomes and Results: Data were analysed using reflexive thematic analysis. Three central themes were identified from the interviews: (1) participants discussed parental uncertainties as to whether they were doing the right thing for their child; (2) while participants were in support of bilingualism, they were not always confident that they were providing the right advice and found it difficult to in keep up to date with relevant, evidence-based research; and (3) participants highlighted a need to shift towards a more inclusive and culturally diverse practice. Conclusions and Implications: This is the first qualitative study to understand the perspectives of SLTs working with autistic bilingual children. We identify several key difficulties in supporting access to language learning, and these findings have immediate and longer-term implications for supporting SLTs, and in turn, the children and families they support.