The point at which political ecology meets religion needs greater study. Whilst religion is more important in the social sciences and humanities today, its importance in relation to issues of concern to political ecologists is only partly addressed. World religions in particular are often neglected, yet can motivate human action in ways that are ripe with political, economic and ecological meaning. Ritual is an important aspect of religion, with the act of pilgrimage particularly insightful as to how some practices can have an enormous impact on both people and environment. Indeed, political ecology is ideally placed to uncover how pilgrimage – a temporary migration of people – can reflect, reinforce or sometimes challenge unequal power relations based on wealth, health, ethnicity, caste, gender or mobility, and with what ecological implications. This chapter explores the political ecologies of religion in relation to pilgrimage through a case study of the hajj: the annual journey to Mecca and Medina in Saudi Arabia made by millions of Muslims. The chapter is structured as follows. First, it summarizes selected research that connects political ecology and religion. It then highlights the historical and geographical importance of religious pilgrimages, including the hajj. The focus is thereafter on governance and the hajj, detailing in particular state practices including those by the main pilgrim-receiving country (Saudi Arabia) and one exemplar of a major pilgrim-sending country (Malaysia). Subsequently, I briefly consider the role of wealth and consumption, health, and civil society activism in relation to the hajj, before concluding with a call for further research.