Quantum computing is rapidly emerging as a transformative technology with the potential to revolutionize enterprise systems across finance, supply chain, pharmaceuticals, cybersecurity, and advanced analytics. Despite its immense potential, integrating quantum computing into enterprise architectures remains a major challenge due to technological immaturity, hardware limitations, lack of expertise, and absence of standardized integration models. This research article proposes conceptual models for integrating quantum computing with existing enterprise systems and describes how enterprises can adopt hybrid quantum–classical approaches. The paper presents a Quantum Integration Reference Model (QIRM), a Hybrid Quantum Enterprise Architecture (HQEA), and a Quantum Readiness and Adoption Model (QRAM). It also discusses technological, organizational, and process-level enablers and barriers. The article contributes to theory and practice by providing systematic frameworks for researchers, architects, CIOs, and digital strategy teams.