There is an urgent need for accessible purification and separation strategies of atomically precise metal clusters in order to promote the study of their fundamental properties. Although the separation of mixtures of atomically precise gold clusters Au25L18, where L are thiolates, has been demonstrated by advanced separation techniques, we present here the first separation of metal clusters by thin-layer chromatography (TLC), which is simple yet surprisingly efficient. This method was successfully applied to a binary mixture of Au25L18 with different ligands, as well as to a binary mixture of different cluster cores, Au-25 and Au-144, protected with the same ligand. Importantly, TLC even enabled the challenging separation of a multicomponent mixture of mixed-monolayer-protected Au-25 clusters with closely similar chemical ligand compositions. We anticipate that the realization of such simple yet efficient separation technique will progress the detailed investigation of cluster properties.