The 1996 memoir All Souls: A Family Story from Southie by Michael Patrick MacDonald has been highly praised for its portrayal of a white urban underclass in South Boston. Few commentators, however, have observed that the Catholic origins of the author, and the distinctly Catholic milieu of the neighborhood he describes, shape the worldview, vocabulary, and psychological attitudes on display throughout the book. This article considers the Catholic sensibilities that inform MacDonald’s narrative. When examined in light of the traditional understandings of religion as an interplay of creed, code, and cult, the Catholics of All Souls are clearly immersed in the cultic aspects of their religion. In addition, they adapt a particular trope derived from Catholic tradition, that of the Guardian Angel, to cope with the difficulties of their socioeconomic plight. Further, the author indicates that on a personal and emotional level, he conceives of his own life and his role in the family as deriving from the figure of the Guardian Angel.