<p>Synthetic molecular systems with allosteric regulation capabilities find applications in purification, sensing, molecular delivery and catalysis. Allosteric regulation, often observed in enzymes, involves the binding of an effector at an allosteric site, which results in the modulation of the function of an active site. Recent efforts have produced synthetic systems that exhibit allostery. Metal–organic cages (MOCs) offer a versatile platform for this purpose due to their three-dimensional structures and simple preparation through self-assembly, enabling the incorporation of multiple binding sites within a single structure. Their structural diversity, tunable cavity sizes and functional adaptability allow effective encapsulation of various guest molecules. Allosteric effectors can serve as chemical triggers to induce structural changes in MOCs through reversible post-assembly modifications, using dynamic covalent bonds or intermolecular interactions. Here we highlight recent advances in using MOCs for allosteric regulation, focusing on design principles, applications and future challenges in this emerging field.</p><p></p>