This dissertation examines the role of the Catholic Church in defining racial categories and construction of the social order during and after the Spanish conquest of Mexico, then New Spain. The Catholic Church, at both the institutional and local levels, was vital to Spanish colonization and exercised power equal to the colonial state within the Americas. Therefore, its interests, specifically in connection to internal and external “threats,” effected New Spain society considerably. The growth of Protestantism, the Crown’s attempts to suppress Church influence in the colonies, and the power struggle between the secular and regular orders put the Spanish Catholic Church on the defensive. Its traditional roles and influence in Spanish society not only needed protecting, but reinforcing. As per tradition, the Church acted as cultural center once established in New Spain. However, the complex demographic challenged traditional parameters of social inclusion and exclusion which caused clergymen to revisit and refine conceptions of race and gender. In this way, the establishment of the colonial church was not a simple transfer of the institution from Spain to the Americas, but a translation of older traditions according to colonial circumstances. This dissertation analyzes contact points between the Church and subalterns and the discourses and concepts that informed clerical practices. Specifically, it examines institutional level debates on subaltern piety, tools for religious conversion (priest evangelization manuals and sermons), priests’ roles in the racial classification of their parishioners, and the intersection of race and gender in the lives of subaltern nuns and lay religious women. Both the Spanish Crown and the Church were deeply invested in the perpetuation of Spanish hegemony and the evolution of concepts like race and gender were key developments in this process. By assessing race from the views of both the Spanish church and subalterns, and emphasizing the role of the local parish priests, this dissertation explores this development from a new perspective.