Set against the view that development indices provide objective assessments of the human condition, in this research, I demonstrate that indices are deeply political and emerge from specific and embodied histories and geographies. This study traces the emergence and subsequent politics of the “Community Well Being Index,” hereafter the CWB, an index designed to measure the conditions of Indigenous communities in Canada that was developed in the early 2000s by researchers at the Department of Indian Affairs and Northern Development in collaboration with social scientists at the University of Western Ontario. Drawing theoretical contributions from performativity scholars, as well as postcolonial, settler colonial and critical development literatures, my research explores how the index, as a historically, socially, technologically contingent tool, actually produces the world it sets out to measure. Through analysis of interviews with designers and users of the index, observation of its presentation, and a review of official documents in which the index is elaborated, I trace the multiple and at times contradictory ways in which the CWB has come to matter in shaping development common- sense, constituting Indigenous subjectivities and allocating responsibility surrounding development interventions. I contend that, notwithstanding its use in advocating for the improvement of Indigenous peoples’ socio-economic conditions, the index is part of a settler policy and bureaucratic performance that predominantly serves to narrow the development pathways available to Indigenous communities.