One of the fascinating yet seldom explored phenomena in predominantly religious polities in the Middle East and elsewhere is the growing reliance on constitutional courts and their jurisprudential ingenuity to contain the spread of religiosity or advance a pragmatic version of it. In this article, I explore the scope and nature of this phenomenon. I proceed in several main steps. First, I define what may be termed "constitutional theocracy" with its often conflicting legal commitments, political interests, and social realities. Second, I examine the main epistemological, juridical and political reasons why constitutional law and courts are so appealing to secularist, modernist, cosmopolitan, and other non-religious social forces in polities facing deep divisions along secular/religious lines. Third, I look at various modes of interpretive ingenuity drawn upon by constitutional courts in Egypt, Pakistan, Israel, and Turkey in order to contain, limit, and mitigate the resurgence of religiosity in their respective polities. All of these countries have experienced a growth in the influence of religious political movements, with a commensurate increase in the levels of popular support that they receive. Despite the considerable differences in these countries' formal recognition of, and commitment to, religious values, there are, however, some striking parallels in the way that the constitutional courts in these (and in other similarly situated countries) have positioned themselves as important secularizing forces within their respective societies. I conclude by drawing some general lessons concerning the political construction of judicial review and the secularizing role of constitutional courts in an increasingly religious world.