This article traces the development of Catholic ecological hermeneutics over fifty years, leading to Pope Francis’s encyclical Laudato Si’ (2015). Analyzing key church statements, it reveals the expanding biblical sources used and efforts to reinterpret them. The interdisciplinary nature of sustainability and Christian churches’ involvement in academic, ecumenical, and interreligious fora have driven this “hermeneutical effort.” Although not critically examining difficult passages or revising Scripture systematically, Catholic ecotheological reflection has integrated multiple sources into a fruitful dialogue with the Bible, contributing significantly to sustainability. This study underscores the evolution of Christian social thought, emphasizing its capacity to update biblical insights and adapt Catholic Social Teaching for public theology.