Religious institutions and activities play a central role in the social, cultural, and historical development of communities, yet their structured representation in digital knowledge systems remains fragmented and often domain-specific. This paper proposes a formal ontology designed to model religious institutions, roles, practices, events, and activities in a unified and semantically rich framework. The ontology captures both organizational aspects—such as ecclesiastical hierarchies, places of worship, and institutional affiliations—and functional dimensions, including rituals, liturgical events, educational activities, and social services. Developed using Semantic Web standards, the model aims to ensure interoperability, extensibility, and alignment with existing cultural heritage and knowledge organization ontologies. The proposed ontology supports advanced reasoning, semantic querying, and knowledge integration across heterogeneous data sources, enabling applications in digital humanities, cultural heritage management, historical research, and information systems for religious organizations. A case study demonstrates how the ontology can be instantiated and queried to represent real-world religious contexts, highlighting its expressiveness and potential for reuse in multidisciplinary scenarios.