<p>Criminalisation theories have traditionally neglected regulatory criminal law. This paper argues that this approach is unjustified and calls for a change. By showing the historical and contemporary relevance of regulatory criminalisation, it contends that theories in this field should be reconstructed around it, claiming that this shift reveals the authoritarian foundations of modern substantive criminal law. The paper is structured as follows. First, it outlines the pervasiveness of regulatory criminal law in contemporary Western constitutional democracies. Then, it traces its genealogy to premodern police power, highlighting its importance in the development of modern criminal law as public law. Next, it critiques traditional criminalisation theories – the harm principle, the wrongness constraint, and the <i>Rechtsgutlehre</i> – for treating regulatory crimes as marginal deviations from their moral philosophical framework. It discusses the causes of this attitude and its descriptive and normative implications, emphasising that in doing so criminalisation theories nurture the Enlightenment liberal ideal of criminal law as an exceptional <i>ultima ratio</i> while, in practice, they legitimise its extensive regulatory reach and obscure its authoritarian dimension. The paper concludes by exploring the relationship between criminalisation, authority, and political order revealed by recentring these theories on regulatory criminal law and outlining its consequences for addressing overcriminalisation.</p>