People who use drugs have been participating in high level drug policy settings for decades, but little critical work has been done to interrogate ‘drug user representation’ in these highly politicised contexts. The aim of this thesis was to open up this terrain and make a scholarly contribution to understandings of both the theoretical underpinnings and the practices of ‘drug user representation’ in these policy settings. Having done decades of ‘drug user representation’ in these same settings, this thesis provided a unique opportunity for me to critically interrogate the practices involved, their underlying assumptions and the effects of these ‘ways of doing things’ for ‘drug user representation’. This research draws on a range of critical perspectives informed by the “ontological turn” including scholars working across disciplines in poststructuralism, critical feminism, Science & Technology Studies (STS) and posthumanism approaches. A qualitative study design was employed to examine ‘drug user representation’ in high level policy settings (such as the United Nations, Commission on Narcotic Drugs) drawing on documentary sources and semi-structured interviews (n=42) with participants engaged in and involved with ‘drug user representation’ within Australia and internationally. The ontopolitical orientation of the research allowed for a critical focus on questions of representation, performativity, power, and resistances underpinned by a reflexive approach consistent with this orientation. This research shows how, alongside increasing calls for greater involvement of people who use drugs in drug policy processes, dominant discourses and other drug policy practices are constantly working to enact drug user representatives as illegitimate political subjects, even before they get to the ‘policy table’. Despite these negative subjectification, discursive and material effects for ‘drug user representation’, the realities being produced through drug policy practices are not pre-determined and singular but emergent, multiple, and therefore, inherently political, and open to the possibility of being done differently. In the context of these ethico-political implications, this research considers how a greater commitment to caring for ‘drug user representation’ as a neglected and under-valued doing might open up new possibilities for ‘drug user representation’ – what it is and what it might become.