This study utilized a retrospective, population-based cohort of administrative records of 167,319 children who attended school in British Columbia, Canada. The outcomes of standardized English, math, and science exam scores, as well as high school graduation were examined. The associations between poverty and educational outcomes at high school were found to be complex. Children experiencing both household and neighbourhood poverty (i.e., “combined” poverty) at age 13 had significantly lower English, math, and science exam scores at grade 10, as well as having higher odds to not graduate before age 20. The effect of combined poverty was larger than household poverty only or neighbourhood poverty only for English exam scores and for graduating. However, the association between poverty with math or science outcome scores was mixed. Experiencing neighbourhood poverty only was generally associated with lower performance in educational outcomes across children of different immigrant generation status (non-immigrant, first-generation, second-generation), immigration admission category (economic, family, refugee), or region of origin (East Asia and Pacific, Europe and Central Asia, South Asia). However, children of specific immigration backgrounds who experienced household-only poverty appeared to score better on math exams in comparison to children who did not experience poverty from those same groups. Intervention and prevention efforts to reduce childhood poverty that also include immigrant-specific considerations could potentially improve children’s educational outcomes.