Although he is not always recognised as such, Søren Kierkegaard has been an important ally for Catholic theologians since the early twentieth century. I introduce for the first time in English the constructive theological features in the underexplored writings of the Italian Thomist, Cornelio Fabro. In the first section, I set the stage with Fabro’s historical context to show Fabro’s desire to negotiate his loyalty to the Thomist revival after Aeterni Patris and the claims of the modern world. In the (...) second, I focus on Fabro’s recovery of Kierkegaard’s writings as a way into understanding Fabro’s wider project of renewal in Catholic theology. Specifically, I draw upon Fabro’s treatment of Kierkegaard’s Mariology and Ecclesiology as two counter-intuitive examples of Catholic theological renewal. I conclude with some observations regarding how Fabro’s constructive theological contribution deepens and expands current understanding of ressourcement theology in the twentieth century. My aim is not just to narrate a vital moment in the history of Catholic engagement with Kierkegaard, but also to provide a representative entry point for Kierkegaard’s writings to continue to stimulate reform and renewal in contemporary Catholic theology in the wake of the ressourcement movement. (shrink)