Manitoba schools are populated with students from diverse cultural backgrounds. Manitoba’s K to 12 Education Action Plan includes the goal to promote the well-being and inclusion of all students. Hence, it is important to examine the role of curricular documents in including students from all cultural backgrounds. Considering the richly diverse science classrooms in Manitoba and the curriculum vision of forming scientifically literate students, my research asks the following question: What are the affordances and constraints of the Senior 1 Science: A Foundation for Implementation curriculum document for the development of science-literate identities inclusive of diverse cultural backgrounds? I conducted a Critical Discourse Analysis (CDA) of the curriculum document, using the theoretical lenses of critical multicultural education and sociocultural studies. The findings of this study point to the need for a science curricular Discourse that problematizes the taken-for-granted assumption that mainstream science is acultural and universal in its discourses and practices, making evident and challenging the hegemonic colonial and Eurocentric Discourses that are normative in the science curriculum. The grade nine science curriculum document presents affordances to culturally inclusive science education, but many constraints to this goal are still in place. These results may contribute to a more inclusive science curriculum and practice in Manitoba and beyond.