Background: We know little about the lived experiences of people with intellectual disability and how these experiences relate to the social context in which health and wellbeing occur. In particular, little is understood about the role of social support in the lives of people with intellectual disability or the relationship between social support and health practices, the perspective used to understand physical activity in this thesis. This thesis attempts to make a contribution to this knowledge gap by investigating the relationship between a critically important aspect of the social environment, social support, and an equally important aspect of health and wellbeing, physical activity. Objectives: The central research question of this thesis is: What role does social support play in the health practices of people with intellectual disability, specifically in relation to their participation in physical activity?. In answering this question, the thesis had the following aims: To identify good practice when conducting inclusive qualitative research with people with intellectual disability; To develop an understanding of social support for people with intellectual disability; To develop an understanding of the role social support plays in health practices, such as physical activity, for people with intellectual disability Design: The research presented in this thesis used a methodology that places people with intellectual disability at the forefront of their own experiences. The methodological approach is firmly based on the key principles of inclusive research, which meaningfully engages participants, is participant focused, and seeks the active engagement of people with intellectual disability in all research processes. To inform this approach, a systematic mapping of qualitative research methods used with people with intellectual disability was conducted to identify good practice when conducting research which is inclusive of people with intellectual disability. Through this review, a 'blueprint' of inclusive research practices that can be used by researchers to be inclusive of people with intellectual disability as participants was developed and guided the research. In-depth interviews, photovoice and participant observation were used to collect data from seven participants with intellectual disability. Results: Findings suggest participants experience social support in complex and diverse ways. Participants experienced the complex nature of informal and formal support and this Declaration by author This thesis is composed of my original work, and contains no material previously published or written by another person except where due reference has been made in the text. I have clearly stated the contribution by others to jointly-authored works that I have included in my thesis. I have clearly stated the contribution of others to my thesis as a whole, including statistical assistance, survey design, data analysis, significant technical procedures, professional editorial advice, financial support and any o...