The just transition has emerged as a key paradigm in the context of climate action and the transformation toward sustainable economies. However, its conceptualization presents notable diversity that hinders its identification and application from the perspective of regulatory expressions. Therefore, this paper examines the main interpretations of the concept—labor-oriented just transition, energy transition, and socio-ecological transition—arguing that, rather than distinct paradigms, they constitute typologies within a single conceptual framework with epistemological and ontological unity. Building on this premise, a comparative analysis is conducted of regulatory instruments such as Nationally Determined Contributions (NDCs), Biennial Transparency Reports (BTRs), and climate change laws from various countries, assessing how these regulatory expressions align with the different typologies of the just transition. The study concludes that, despite national and sectoral nuances, there is a common foundation based on principles of justice, equity, and inclusion, which supports the existence of a single just transition paradigm whose practical manifestations converge in a process of structural change with integrated social, economic, and environmental implications.