Regionalization is a fundamental process and an essential approach for geographers; however, the notion of regionalization itself appears undermined. First of all, it is impacted by many criticisms directed at the notion of region with which it is associated, due to the emergence of other competing notions, such as those of territory, space, and place. Second, one could ask whether regionalization is still relevant in the era of globalization, world metropolises, transnational networks, and generalized worldwide connections. To better understand the evolution of the notion in the discipline of geography, two ways of defining it will be shown, one at the intrastate level, where it can be used for purposes of action or knowledge development, and the other on the global scale (macroregional integration).