Introduction: The use of telehealth to provide behavioural services for people with intellectual/developmental disabilities (IDD) is increasing. However, there are no prospective evaluations of stakeholder perspectives relating to this, which may have implications for uptake of such services. This study aimed to identify factors influencing family carer and professional willingness to use telehealth for behavioural support in the UK. Methods: A Delphi consultation was conducted in four rounds with two panels (professionals and family carers), aiming to reach consensus on the most influential advantages and disadvantages/barriers to participant's willingness to use telehealth. Results: Thirty‐six and 22 items reached consensus as being influential for professionals and family carers respectively. Factors identified by each panel differed, with professionals focusing on the logistics of support whilst family carers highlighted factors relating to the quality of support. A common solution to the barriers identified related to combining in‐person and telehealth methodology. Implications: A range of factors were identified that are influential to professional and family carer willingness to use telehealth for behavioural support. These factors suggest advantages to maximise and barriers to overcome in order to increase uptake of telehealth services in this field.