The Métis are a post-contact Indigenous People whose origins lie in the buffalo hunting economy of the late 18th-/early 19th-century northern plains, where their mobile society flourished, in relations with their First Nations relatives, by the mid-19th century. Their culture evolved through a distinctive combination of identity, language, land tenure, economic niche and family kinscapes. Much of the literature pertaining to Métis populations has taken for granted the self-identification by respondents of large-scale surveys and the census as a basis for estimating socio-demographic and epidemiological characteristics. This is deeply problematic to the extent that it diminishes the power of Métis governments (provincially) to provide policy-relevant estimates of their citizens’ population-level characteristics. In this chapter, we will explore this literature with an eye for investigating how an over-emphasis on self-identification can artificially inflate Métis population data for citizens of the Métis nation. Drawing on a conceptual case study, we will explore the current data situation of the Métis nation in Canada and suggest that compared to other Indigenous nations in other nation-states, Métis data sovereignty is limited to geographical regions with no national strategy, and thus is still largely reliant on existing and externally generated national census data.