In this article, we argue that ontology’s and semantic web technologies are important to the future of Enterprise Architecture (EA). The article outlines the value and need for dynamic models of enterprises, and points to semantic web technologies as the most promising way to do this. First, we observe that Enterprise Architecture (EA) models that could be distributed, federated, and executed will be essential to support the needs of agile enterprises to respond rapidly to opportunity and change. As the value propositions, applications and uses of EA move toward executable models, we note that ontology’s and semantic web standard languages are well suited for the next generation of EA solutions. Semantics involve knowledge representation and semantic web technology not only makes it easier to aggregate and analyze information, but also paves the road to active or executable enterprise architectures driven by its capabilities for expressing, querying and federating enterprise models and information.