This book offers the first comprehensive English-language analysis of regional paradiplomacy in Poland and engages with the latest research on the phenomenon of paradiplomacy both globally and in Poland. As regions increasingly engage in international cooperation beyond traditional state diplomacy, this study provides essential insights into how voivodeships, the primary administrative-territorial unit in Poland, navigate global partnerships and pursue autonomous foreign policy objectives. Drawing on extensive research across all 16 Polish regions, the author examines both the theoretical foundations and practical manifestations of regional paradiplomacy. The work reveals how voivodeships have developed sophisticated international networks, particularly with Ukraine and China, while operating within Poland's unitary state structure. Through comparative analysis, the study identifies common patterns and unique approaches in regional foreign cooperation, from institutional frameworks to strategic priorities. Particularly timely given current geopolitical tensions and the war in Ukraine, this book demonstrates how regional authorities have become crucial actors in international relations. The author provides a holistic framework applicable to other post-communist states developing similar paradiplomatic activities. Essential reading for scholars of political science, public administration, international relations, and foreign policy, this work also serves practitioners in regional government, think tanks, and NGOs seeking to understand the evolving landscape of sub-state diplomacy in contemporary Europe.