This study addresses constitutional secularism in India by examining how the Supreme Court of India has defined and demarcated religion, religious practice, religious organizations, and religious freedom. The Court not only plays an important adjudicatory role in a host of areas related to religious freedom and the intervention of the state in religious institutions and practice, but also actively intervenes in and shapes public discourse. One of the reasons the judiciary can play this role is the legitimacy it enjoys in public perception. Based on an analysis of Supreme Court rulings, this monograph argues that the Indian state has pushed its reformist agenda at the expense of religious freedom and neutrality. There are two broad claims made: First, through its rulings the Supreme Court consistently has sought to homogenize and rationalize religion and religious practices, particularly of Hinduism. Second, although the impetus for the Court’s decisions has its origins in a liberal-democratic conception of secularism and the nation-state, there is a significant overlap between the judicial discourse and the evolution of Hindu nationalism. This development has significantly narrowed the space for religious freedom and strengthened the hand of Hindu nationalists, whose ideology is based on a monolithic conception of Hinduism and intolerance of minorities.