This thesis explores shifting ideas of the secular in Kolkata, India, through an ethnographic account of socio-political life in the city's southern suburbs. This part of the city was transformed by the arrival of Bengali Hindu refugees from East Bengal from the late 1940s onwards. The refugees achieved rehabilitation and political representation to a significant degree through an alliance with communist and socialist political parties, contributing to the election of the Left Front government from 1977 onwards. However, the political culture of the city and state is transforming in the aftermath of the electoral defeat of the Left Front in 2011. The thesis explores this post-communist conjuncture in the state's political culture, and how prevalent understandings the secular respond to this changing political landscape. The parliamentary Left in contemporary India has been defined by its commitment to the constitutional ideals of socialism, secularism and democracy. The first section argues that communism allowed the refugees to achieve rehabilitation and political representation within, rather than against, the Indian state. They also reproduced religious traditions in the city that contributed to their constructions of community and political values in ways which are inextricable from each other. The second section looks more specifically at political secularism and its relation to statecraft and democratic processes in the form of constituencies in this part of the city. The political parties struggle for control of public religious spaces, which are important for securing their influence at the grassroots, and in the process articulate distinct forms of secularist politics which co-opt public rituals. They also engage in cultural politics designed to articulate secular or non-religious public spheres. Through ethnographic evocations of public life in Kolkata's southern suburbs, I suggest that the Left Front failed to achieve ideological hegemony, and its secularism never wholly displaced religious framings of political culture in the state. I argue, secondly, that the categorical formations of religion and politics - and therefore ideas of the secular based on this conceptual distinction - are ideological constructions and therefore open to constant reinterpretation. My interlocutors, both within and outside the party, remain committed to secular futures, but they creatively search for ways to articulate secularist politics which do not necessarily rely on categorical distinctions of the past. Therefore, I search for the secular with them, disaggregating the discursive constructions on which secularist politics are founded. The elusive secular is found, in my analysis, through the ways in which residents of the city continually (re)conceptualize the contours of their public, political lives.