Abstract: Context: Whereas academic discourse on socio-environmental justice (SEJ) globally has focused on race, ethnicity and wealth, and gender inequalities, research on SEJ in relation to children, their well- being and waste management in Africa has remained neglected.This paper focuses on the Almajirai, children in the Islamic educational system, and critically examines SE] in Almajirai involvement in the solid waste management (SWM) system of cities in northern Nigeria. Data Source and Method: The study is situated in the city of Zaria, Kaduna State, Nigeria. Mixed methods approach used for data collection included consultations with key stakeholders, ethnographic and field observations; key informant interviews (Klls), questionnaire survey of 350 respondents sampled purposively, and a critical review of literature. Percentages were utilized for analysis of quantitative data while quotations and transcriptions were made from interviews. Findings: Findings indicate that while many Almajirai contribute to environmental well-being through collection, disposal and recycling of waste, they often suffer unbridled socio-environmental injustice in their quest for a livelihood and also for their perceived association with insecurity in northern Nigeria. Conclusion: In the light of the findings and the overarching juvenile-related sustainable development goals (SDGs) targets, the paper rethinks the role of Almajirai in SWM while articulating possible policy benefits of scaling up engagement with Almajirai in the post-2015 development era. Keywords: Almajiraé, solid waste management; sustainable development goals; well-being; socio- environmental justice