This book offers a new theory of federalism. The work critically discusses traditional federal theories and builds on theories that focus on the dynamics of federalism. It offers a definition of federalism and federal organizations that encompasses both new and old types of multi-tiered system. Unlike traditional federal theory, it is well-suited to research both multinational and mononational systems. It also takes into account the complexity of these systems, with bodies of governance at the local, regional, national, and supranational level. The book is divided into three parts: the first part outlines the contours of dynamic federalism, based on a critical overview of traditional federal theory; the second part develops comprehensive indexes to measure autonomy and cohesion of multi-tiered systems; and the third part focuses on the dynamics of federal organizations, with a special focus on institutional hubs for change. Dynamic Federalism will be an essential resource for legal, social, economic, and political scholars interested in federalism, regionalism, and de/centralization.