The scholarly attainments and expansive self-education of the eighteenth-century Baptist theologian John Gill (1697-1771) have long been noted and praised by those who have read his vast corpus of writings. In recent decades, a strand of scholarship focusing on Gill’s impressive and varied use of sources has developed. Scholars such as Richard Muller, Mark David Rathel, Hong-Gyu Park, and Steven Godet have advanced the thesis that Gill’s knowledge of the church fathers and Reformed orthodox theologians was expansive, and his widespread use of them significant, such that Gill cannot be properly understood except as a student of the church fathers and representative of the Reformed orthodox tradition. This paper will aim to contribute to this strand of scholarship by examining Gill’s use of sources in his ecclesiological writings. It will argue that Gill intentionally made use of patristic and Reformed paedobaptist sources instead of credobaptist sources in the presentation of his ecclesiology. His ecclesiological writings, therefore, exhibit a spirit of Baptist catholicity that takes seriously a great tradition of Christian theological reflection, even in reference to the Baptists’ most controversial distinctives. It will furthermore propose his thorough engagement with Christian history as an object for retrieval by the Evangelical Baptist catholicity movement. In service of this thesis, the paper will examine his extensive use of patristic sources, his creative and positive use of Reformation and post-reformation paedobaptists in support of Baptist distinctives, and his refusal to interact with Baptist sources even when discussing ecclesiology, the locus of theology in which Baptists are most distinct. The paper will conclude by offering observations on the similarities in method proposed by the Evangelical Baptist catholicity movement and the method employed by Gill.