This article examines the significant ecclesiological contribution of the French Dominican theologian Yves Congar. In particular, it is argued that the attempt to account for both the divine and human dimensions of the Church was central to Congar's ecclesiological program. Beginning with his early work Chrétiens désunis , Congar recognised the Church both as an extension of the divine communion (Ecclesia de Trinitate) and as a human society (Ecclesia ex Hominibus ), united through the mediating work of Christ (Ecclesia in Christo ). This divine—human tension pervaded his theology of the laity, his treatment of appropriate reform in the church, and his understanding of the appropriate role of Church hierarchy. As he turned his attention increasingly toward pneumatology later in his career, this basic orientation was deepened and enriched. Throughout his career, Congar aimed to maintain fidelity to his tradition while engaging the challenges of the contemporary world.