The article discusses regionalism in the modern world economy, focusing on the history, current trends, and main integration projects. It explains that regionalism involves uniting countries into larger regions with free movement of certain factors. The old regionalism aimed to boost international trade and security, while the new regionalism focuses on deep integration processes. Countries consider strategic, political, and economic factors when signing integration agreements. Mega-projects like the Trans-Pacific Partnership simplify trade rules and reduce disputes. Overall, regional integration is evolving towards greater unity and simplification in the global trading system.