This paper offers an institutional explanation of inegalitarian gender attitudes in countries with significant Muslim populations; I employ theories of status belief construction as a social psychological mechanism and propose that formal institutions backed by religious authority have powerful feedback effects on gender attitudes and can drive significant attitudinal change. This explanation both complements and extends upon existing explanations that employ either a putative Islamic culture or economic modernization as an explanation. Using data from the fourth and fifth waves of the World Values Survey, I demonstrate that institutions restricting the legal rights of women significantly predict inegalitarian gender attitudes of individuals in those countries and that these institutions are nearly as important as female labor force participation, female parliamentary representation, and level of democracy combined. To test the theory within-country as well as between-countries, I examine the federal state of Nigeria, and to test whether institutional reform can affect attitudes, I examine the sweeping gender law reforms implemented in Morocco since 2004. Both cases support the assertion that religiously legitimated institutions can have significant effects on shaping individual attitudes. Such top-down institutional reform has important implications for scholars of religious and cultural change, status inequality, and democratization.