AbstractFamed for its austerity, Jansenism nonetheless prompted a slew of salacious street‐songs throughout the seventeenth and eighteenth centuries. If historians have increasingly examined early modern urban singing practices, underlining the social porosity and intergenerational hold of many street‐songs, little research has been devoted to unpicking what songs offer to the study of religious history. The aims of this article are two‐fold. First, it seeks to assess the value (and sketch out some limits) to street‐songs as a source in recovering some of the more popular facets of religious controversies — here, the Jansenist movement. Second, and as a corollary of this, the article uses street‐songs to emphasise the political sophistication to popular interest in Jansenism. It suggests that this antedated and ran alongside the convulsionary movement, which has been typically viewed as the apogee of popular engagement with Jansenism. This article first considers how the hold of specific literary themes and popular tunes over generations impacted discussions on the Jansenist debate, before turning to examine the suitability of songs in capturing devotional and theological content, and finally discussing the complexity of the popular political and ecclesiological ideas on the Jansenist movement that the street‐songs conveyed. The article ultimately seeks to underline the value of street‐songs as a source on urban popular religious expression.