Background: The present study examines the relationship between stereotypical beliefs about people with intellectual disabilities, desire for social distance, and general knowledge about human sexuality with attitudes towards the sexuality of adults with mild intellectual disabilities. Method: Two hundred fifty participants from staff, family and community samples completed an online set of questionnaires. Results: Higher agreement with stereotypical beliefs and lower sexual knowledge were associated with less normalising and more paternalistic attitudes towards the sexuality of adults with mild intellectual disabilities. Higher agreement with stereotypical beliefs was also associated with more negative attitudes. On the other hand, willingness to interact with these adults was associated with more normalising and less paternalistic attitudes. Conclusions: Interventions that aim to support adults with intellectual disabilities in relation to their sexuality should also address the perceptions of their support network towards them as individuals with disabilities, as well as their knowledge about sexuality.