GaN-based UV light emitting devices suffer from low efficiency. To mitigate this issue, we hybridized GaN nanowires (NWs) grown on Si substrates by plasma-assisted molecular beam epitaxy with solution-processed p-type MnO quantum dots (QDs) characterized by a wider bandgap (~ 5 eV) than that of GaN. Further investigations reveal that the photoluminescence intensity of the GaN NWs increases up to ~ 3.9-fold (~ 290%) after functionalizing them with p-MnO QDs, while the internal quantum efficiency is improved by ~1.7-fold. Electron energy loss spectroscopy (EELS) incorporated into transmission electron microscopy (TEM) reveals an increase in the density of states in QD-decorated NWs compared to the bare ones. The advanced optical and EELS analyses indicate that the energy transfer from the wider-bandgap p-MnO QDs to n-GaN NW leads to substantial emission enhancement and a greater radiative recombination contribution, due to the good band alignment between MnO QDs and GaN NW. This work provides valuable insight into an environmentally-friendly strategy for improving UV device performance.