In 2017, school board trustees in Ottawa, Ontario, voted to close Rideau High School, an urban secondary school in a historically marginalized neighbourhood. The school board had argued that low enrolment at Rideau HS, and the resultant inability of the school to offer a full range of course choices, made closure the only viable option. To many people in the affected communities, however, the closure decision was seen as a form of discrimination against the school's marginalized student population, which included many new immigrants, refugees, and Indigenous students. This article draws upon research from the US and the UK that emphasizes the spatial dimensions of urban education, along with the existing research on school closures in Ontario in order to explore this particular school closure decision from an urban, political, socioeconomic, and historical perspective. By focusing on a case study area in eastern Ottawa, this article incorporates both a narrative history of Ottawa school board policies and a quantitative analysis of local demographic data. The argument here is that the closure of Rideau HS should be understood in the context of a series of interconnected challenges faced by the school, including a marginalized student population, a negative reputation, and low student enrolment. In turn, these challenges should be understood in the context of socioeconomic disparities between neighbourhoods in the area and a history of ineffective policies at the school-board level, including relatively lax student transfer policies. These findings indicate the inadequacy of the narrow economic measures that Ontario school boards use to determine school closure decisions, and suggest that school boards should engage in more robust community engagement before closing marginalized urban schools. A proposal to establish an official "community hub" within the active high school, which was supported by the community but not by the school board, is examined as a concrete alternative to closure.