This thesis examines the academic researchers who studied race, ethnicity, and race and ethnic relations in Canada between 1880 and 1940. The thesis considers how questions of race/ethnicity and race/ethnic relations were debated in the Canadian milieu of large-scale immigration. The thesis is based on the discussion of these questions in the universities and the evolving social science communities. The discussion of race/ethnicity in Canada incorporated the evolving political discussion of Dominion autonomy within the British empire and was also shaped by the conditions of science and social science in Canada. Influenced by these factors, Canadian liberal scholarly opinion moved away from the extremes of nativism, as well as rejecting imperialist views of race, and reflected more moderate perspectives on ethnic diversity during the period of nation-building. By the early twentieth century, Canadian liberal academic thought had come around to at least a partial acceptance of cultural diversity, which was nonetheless subordinated to the idea of a culturally-based nationality and the beneficent state protection and assisted assimilation of ethnic minorities. Academic thought on race/ethnic relations subsequently mirrored a North American dialogue on cultural diversity, as well as reflecting the conditions of Canadian social science in the 1920s and 1930s.