This discussion paper explores how African countries can mobilize additional development finance by enhancing public sector efficiency. Using Nigeria as a case study, it illustrates the pathways through which targeted reforms can create significant fiscal space. These include improving public procurement processes to reduce inefficiencies; lowering the cost of tax administration, and reducing functional overlaps between institutions. Together, these reforms enable more effective and efficient use of existing resources, thereby freeing up additional funds to support development priorities. While the findings are rooted in the Nigerian context, the paper underscores that the overarching insights and policy lessons derived can inform wider and more nuanced policy conversations, offering valuable lessons for other countries on the continent seeking to improve their fiscal capacity and accelerate progress towards their development objectives through internal systemic improvements.