Established in 1934 under the aegis of the Archbishop of Cincinnati, John T. McNicholas, the National Legion of Decency's primary objective was to monitor the morality of American films and, as far as possible, guide the decisions of producers and directors. Working in tandem with the Production Code Administration, the Legion wielded significant influence until the 1960s. This paper aims to outline new research trajectories regarding the relationship between the Legion and the Holy See, drawing on the documentation that has emerged since the 2020 opening of the Vatican archives for the pontificate of Pius XII. In doing so, it will highlight key turning points, parallels, and conflicts where they arise.