ABSTRACT Even as essential definitional and conceptual issues related to ‘minilateralism’ remain unresolved, conjecture has arisen as to the future trajectories of established institutions, such as the Trilateral Strategic Dialogue (TSD), AUKUS, and the Quad. – Could they evolve into formal military alliances over time, or serve as the foundation of a new organisation aimed at providing regional security governance? To systematically evaluate such contingencies this article traverses a set of interrelated conceptual issues relating to minilateral institutionalisation. It seeks to differentiate minilaterals in terms of their ‘hybridity’ both in structural composition and functionality, and ascertain what this implies for their institutional progression. This process assists us in identifying on what grounds minilaterals might potentially evolve into a more formalised institutional paradigm – either (i) a military alliance or (ii) a cooperative security governance organisation. This foregoing conceptual apparatus is then brought to bear of on the case studies above to draw out clues as to their prospective institutional development pathways. The article concludes that, while such putative institutional transformations remain conceivable, in none of the cases is a particular pathway preordained. Instead, minilaterals may simply continue to adapt within the parameters of their present institutional boundaries.