We start by summarizing recent research on system justification theory, highlighting studies conducted outside the U.S. to expand the cross-national scope of the theory. Next we describe major findings in social and political psychology pertaining to religiosity, political conservatism, and various forms of system justification before turning to a specific case of entrenched inequality, namely the sectarian political system in Lebanon. We discuss the results of a nationally representative survey of 500 Lebanese adults conducted in 2016. Consistent with system justification theory, we observed that religiosity and political conservatism were positively associated with general and economic forms of system justification as well as support for the sectarian political system in Lebanon. We situate these findings in a broader historical and cultural analysis of Lebanon and other sectarian societies and highlight ways in which applying psychological theories and methods to novel and distinctive socio-ecological contexts can lead to practical insights and perhaps even policy recommendations.