This study stages an illuminating analysis of religious politics in Dar es Salaam and Tanzania from below. At its heart is an original account of Muslim political mobilisation in Tanzania that foregrounds the everyday lives of urban actors in Kariakoo, a super-dense market district at the centre of Dar es Salaam. Under British colonial rule, Kariakoo was Dar es Salaam‟s principal African residential neighbourhood; the beating heart of the city's lively cultural scene and the cradle of Tanganyika‟s African nationalist movement. Today, Kariakoo has grown into one of the most important commercial districts in the East African region. In 2012 and 2013, it was also the site of episodes of Muslim mobilisation which led to clashes with state police and armed forces. Drawing on rich data derived from fifteen months of ethnographic fieldwork in the neighbourhood, I ask what the everyday life of Kariakoo reveals about religious politics in Tanzania. More specifically, I use it to investigate the intersections between Muslim mobilisation, informal livelihood practices developed by urban users in response to escalating conditions of economic precarity, and popular discontent concerning entrenched inequalities and uneven development along religious lines. By drawing together several innovative research trajectories in the fields of religious and urban studies, I am able to hold together the notions of the religious and the urban in a manner that spotlights just how integral religion is to Kariakoo as an urban ecology. The subsequent discussion reveals the remarkable dynamism of Muslim social practices and modes of affiliation when considered as numbering among the everyday livelihood practices that are employed by urban users in Kariakoo. This study brings a more nuanced explanatory frame to bear on the contemporary realities of Muslim activism and religious politics in Tanzania and beyond than those that prevail in much academic and media commentary.