<p>This paper examines the role of informal institutions in poverty reduction in sub-Saharan Africa (SSA) by focusing on two key variables: early marriage and female entrepreneurship. Indeed, the role of institutions in poverty reduction has been the subject of several theoretical and empirical studies in the literature. However, the role of informal institutions in explaining poverty has long been ignored in the literature. Very few studies highlight the importance of informal institutions as explanatory factors of poverty. Most studies focus on formal institutions. This paper fills this gap. We estimate a panel model for 44 sub-Saharan African countries over the period 2002–2021. Applying the instrumental variables (IV) method, the results show that the informal institutions variables have inverse effects on poverty. While early marriage positively and significantly affects the poverty rate and depth of poverty, female entrepreneurship plays an inverse role by negatively and significantly influencing the depth of poverty. These results highlight the importance of taking informal institutions into account in poverty reduction policies in SSA. Specifically, efforts to combat early marriage and encourage female entrepreneurship contribute significantly to poverty alleviation in the region.</p>