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. 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. 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. 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. 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. What is already known on the subject Research suggests that autistic children currently have fewer opportunities to maintain bilingualism compared to neurotypical peers. Despite the lack of evidence, many families remain concerned that bilingualism will have a negative impact on their child's development. To date, little is known about the perspectives of speech and language therapists (SLTs) who play a significant role in supporting the development of autistic bilingual children. This is the first study to provide an in-depth qualitative analysis of the experiences of SLTs working with autistic bilingual children and their families in the United Kingdom. What this study adds The results highlight a number of reoccurring barriers in providing optimal support: first, frequently cited concerns about bilingualism from parents that link to a lack of understanding about autism and the role of SLTs more generally. Second, SLTs do not have confidence in the assessments and tools available and described a lack of emphasis on cultural factors in practice. Many SLTs were concerned about the limited options for resources and interventions available in other languages, which could be challenging for parents who were less proficient or confident communicating in English. Third, SLTs reported having limited opportunities to keep up to date with relevant research to support their decision-making processes. What are the clinical implications of this work? These results have several important implications for practice-they highlight the need for more inclusive practices where possible, a need for more diversity within the profession and further opportunities to be provided with evidence-based advice around good practice. The results also suggest a benefit of providing accessible, evidence-based resources for parents about autism and bilingualism, to ensure that research key findings are reaching families.