Economic integration, evolving from inter-state trade relations to intra-continental and inter-continental frameworks, represents a pivotal development in modern economic policy. While integration has generated significant benefits for participating nations, it also raises questions about the distribution of gains and the identity of the primary beneficiaries. Contemporary events, such as Brexit, underscore the continued relevance and complexity of economic integration in shaping global and regional economic dynamics. This paper provides a desk-based review of theory and empirical evidence on economic integration, with a focus on the East African Community (EAC). It examines the background, significance, and objectives of regional integration, highlighting how economic collaboration enhances trade, investment, and corporate growth. The study synthesizes existing literature across conceptual, methodological, and contextual dimensions, assessing the impact of integration on listed companies and overall economic performance in East Africa. Key findings indicate that regional integration facilitates market expansion, resource mobilization, and improved corporate competitiveness, while also posing challenges related to policy harmonization and equitable distribution of benefits. By offering a comprehensive review of theoretical perspectives and empirical studies, this paper provides insights into the mechanisms through which regional integration influences corporate growth. It identifies gaps in current research and proposes directions for future studies, emphasizing the need for more nuanced analyses of firm-level impacts, cross-border regulatory frameworks, and sector-specific outcomes. The findings serve as a reference for policymakers, business leaders, and researchers interested in optimizing the benefits of economic integration while addressing its potential drawbacks.