This study renders an original and constructive Catholic theology of prayer drawing on the work of Hans Urs von Balthasar (1905-1988). Travis LaCouter explores the trinitarian, Christological, ecclesial, anthropological, and eschatological dimensions of prayer in Balthasar's theology, and shows how these combine to give a powerful account of prayer's proper theological scope and purpose. There is also a critical dimension of prayer which is arguably underdeveloped in some of Balthasar's key texts, but which LaCouter shows to have significant dialogical potential with contemporary accounts of parrhesia since Foucault. This approach demonstrates the centrality of prayer to Balthasar's entire theological system and does so in a way which itself constitutes an exercise in Catholic systematics. This study is also distinctive for establishing a method of proceeding through Balthasar's sprawling oeuvre (and the similarly vast secondary literature) by arguing for three "categories" of texts in Balthasar's writings and, separately, three "waves" of Balthasar readers. Thus, this study is a resource not just for those interested in prayer but for anyone interested in reading Balthasar today.