Polymer microparticles (MPs) are widely used to create long-acting injectable formulations due to their ability to enable sustained drug release. This feature can significantly benefit chronic disease management by reducing dosing frequency and improving patient adherence. To support the design and development of polymer MPs, we have compiled a dataset on MPs formed from poly(lactide-co-glycolide) (PLGA), the most commonly used polymer in commercial MP drug products. This dataset, derived from the literature, covers 321 in vitro release studies involving 89 different drugs. It aims to streamline future MP development by providing a reference for the current PLGA MP design space and supporting data-driven approaches such as machine learning. Published with open access, this dataset encourages broad utilization and aims to expand the range of available MP formulations.