Metal halide perovskite quantum dots (PQDs) and perovskite magic sized clusters (PMSCs) exhibit interesting size- and composition-dependent optoelectronic properties that are promising for emerging applications including photovoltaic solar cells and light-emitting diodes (LEDs). Much work has focused on developing new synthesis strategies to improve their structural stability and property tunability. In this paper, we review recent progress in the synthesis and characterization of PQDs and PMSCs, with a focus on the impact of different molecular ligands on their surface passivation and interconversion. Moreover, the effect of capping ligands on ion exchange during synthesis and doping is discussed. Finally, we present some perspectives on challenges and opportunities in fundamental studies and potential applications of both PQDs and PMSCs.