The oxygen absorption properties of high entropy hexagonal manganites have been studied, using thermogravimetric analysis (TGA), high-temperature X-ray diffraction (HT-XRD) and X-ray absorption nearedge structure (XANES). High configurational entropy compositions were found to stabilize the layered hexagonal structure and to improve the kinetics of oxidation compared to previously reported hexagonal manganites. The oxygen storage capacity was high (δ > 0.3 in RMnO3+δ) for all nanocrystalline samples, with increased oxygen absorption by adding Ti and Tb. Bulk high entropy materials also displayed strongly improved oxygen absorption capacity and kinetics compared to previous reports. The oxygen absorption properties were found to be rather insensitive to variations in chemical composition, implying that structural disorder itself is contributing to the improved oxidation kinetics. Improved properties and insensitivity to exact rare earth composition enhances the application potential of hexagonal manganites for oxygen separation and release.