Belying assumptions about Catholics and science grounded in the old science-religion warfare model in the 1920s, two liberal Catholic intellectuals contributed in some important but overlooked ways to the discourse where prominent scientist-popularizers and other intellectuals constructed the public understanding of evolution and the Scopes Trial in the mid-1920s US. This article explores publicly-disseminated articles and archival correspondence between Catholics and non-Catholics on these topics, concluding that the manner in which the former supported evolution and opposed the Scopes prosecution may have unintentionally fostered scientism and religious modernism, rather than Catholicism, in the public square. Conditioned by their own Progressive-Era experiences and intellectual training, renowned liberal Catholics Fr. John A. Ryan, board member of the American Civil Liberties Union, and Michael Williams, editor of Commonweal magazine, framed their arguments directed at non-Catholic intellectual elites almost exclusively in social and biological science to the exclusion of religion. They did so even as public intellectuals and prominent scientists of modernist faith, like Henry Fairfield Osborn of the Museum of Natural History, constructed a public image of evolution that blended religion, philosophy and science when assigning meaning to the Scopes Trial. This study broadens the view of science-religion conversations surrounding evolution in the 1920s by integrating voices usually omitted from the story while further complicating the still-resonant ‘creationist-' evolutionist’ paradigm.