The principle of fair labelling has informed the creation of international crimes and other concepts of international criminal law since the modern inception of this discipline. In particular, it was the symbolic and condemnatory import of international labels such as genocide and crimes against humanity that partly motivated their introduction as offences separate from domestic ordinary crimes. Paradoxically, fair labelling has received marginal attention in legal scholarship and practice. Moreover, frequent instances of relabelling known as ‘recharacterisation of crimes’ may not be entirely consistent with that principle, inviting further analysis thereof. In this context, the purpose of this article is to provide a more systematic and comprehensive analysis of the principle of fair labelling in international criminal law, particularly in light of the phenomenon of recharacterisation of crimes. Its central claim is that fair labelling is as a fair trial right which precludes recourse to recharacterisation in certain circumstances.