Thesis advisor: Hosffman Ospino / Roughly one-third of U.S. Catholic parishes serve parishioners of multiple cultural, ethnic, and/or linguistic groups. In these “shared parishes,” the possibility and meaning of community across boundaries is an urgent question. This dissertation examines the role of ritual in the formation of community in diverse parishes. Critiquing prevailing ecclesiological models of unity in diversity that inadequately address structural sins of racism and xenophobia, I argue for an understanding of communion as a task of the local Church, embodied ritually in solidaristic practice. Then, establishing a conversation among ritual studies and U.S. Latinx discourses of border identity, I propose an understanding of the shared parish as a kind of borderland – as a place where a subjunctive communal identity can be negotiated ritually through embodied engagement. Methodologically, the dissertation is grounded in an ethnographic study conducted over five years at St. Mary of the Angels, a small, diverse parish in Boston, MA. Weaving together historical and archival data from parish, neighborhood, and archdiocese; participant-observation of bilingual Holy Week liturgies; and Spanish- and English-language interviews, the case study foregrounds the dissertation's theoretical work by analyzing how parishioners constructed rituals that facilitated the crossing of cultural, racial, and linguistic boundaries. / Thesis (PhD) — Boston College, 2018. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Religious Education and Pastoral Ministry.