In North America, research has demonstrated that, on average, students racialized as Black lag behind their White counterparts in standardized test scores and high school graduation rates. Researchers have suggested that structural barriers in the North American education system are to blame for these disparities. Racial and ethnic identities and cultures have also been identified as both contributing to, and impeding Black students’ success. In Canada, provincial government and school board inclusive education policies have been introduced over the last decade to address achievement disparities for “diverse” student populations. Despite the wealth of research and some policy interventions, the academic achievement gap persists in Toronto. This study examines underlying academic and social policy discourse on Black students and academic achievement, and investigates how these broader discourses shape local talk and practice in one metropolitan secondary school in Toronto, Ontario. The aim of this study was to determine how school processes, understood discursively may prevent, or reinforce disparate outcomes for Black students. Using a post-structuralist ethnographic approach, participant observation and qualitative interviews were conducted over a four-month period with 12 self-identified Black students (ages 14-18 years). Observations, formal interviews, and informal conversations were also conducted with 14 staff members. Study results suggest that there are multiple competing discourses on Blackness and academic achievement that are historically grounded, and reproduced through academic research and policies, and which were available to students and staff in the specific school environment. This included a dominant discourse of Blackness as damaged/deficit and neoliberal discourses surrounding the market value of diversity and education. White staff members reproduced, and constructed discourse related to culture and Black students, which reinforced marginalizing discourses for Black students. Black students displayed fluid understandings of Blackness, but in describing their academic experiences, also drew on damage/deficit discourses. Students also navigated responsibilized subject positions. In-depth examination of a single student narrative reveals the complexity of competing discourses that shape student subjectivities, and calls attention to the continued need for differentiated gender analyses in attending to Black students’ experiences. The findings of this dissertation suggest that in-depth attention to schools’ overall discursive practice, student agency and complex subjectivities is needed to obtain a more comprehensive picture of the experiences of students racialized as Black in Ontario, and to design interventions that support education equity.