Background: Individuals with intellectual disability are subject to stigmatization, even among those providing services to them. Method: Employees from an intermediate care facility (n = 97) and undergraduate students (n = 92) completed measures on their attitudes, beliefs of etiological causes and endorsement of helpful treatments and supports. Results: Overall, participants reported few stigmatizing attitudes and high levels of support for interventions. Differences between employees and students emerged in regard to attitudes and causal beliefs, with employees reporting more support for sheltering and less endorsement of biomedical causes. Among students, those that reported knowing someone with intellectual disability reported less agreement with causal factors as well as differences in what supports were thought to be necessary or beneficial. Conclusions: Attitudes and beliefs are interrelated and while familiarity impacts these views, it does not necessarily lead to greater understanding or endorsement of treatments or supports. The effects of familiarity on attitudes and beliefs should continue to be explored.