Transition metal nitrides with rock-salt structure support significant electronic contributions to thermal transport, distinguishing their response to irradiation-induced defects from that of widely studied fluorite-structured oxides. Here, we report an experimental and modeling investigation of thermal conductivity in proton-irradiated uranium mononitride (UN) across irradiation temperatures of 25°C and 800°C and doses of 0.1, 0.3, and 1 dpa. Temperature-dependent thermal conductivity from 77 to 295 K is measured using spatial-domain thermoreflectance, with defect populations characterized by transmission electron microscopy. A semiclassical transport model is developed to account for electron and phonon contributions, electron-phonon coupling, magnetic scattering associated with 5f electrons, and defect scattering. A counterintuitive thermal conductivity increase of 25–30% is observed after 0.1 dpa irradiation at 25°C, with the measured conductivity at 295 K surpassing all previously reported pristine UN values prior to density correction. The model attributes this anomaly to suppression of crystal-field and low-temperature magnetic contributions to electrical resistivity, suggesting that irradiation-induced disorder modifies 5f electron correlations. At higher doses of 0.3 and 1 dpa, thermal conductivity saturates, with point defects identified as the dominant scatterers. Contrary to the conventional assumption that phonon transport is more severely degraded by atomic-scale defects, reductions in electronic and phonon contributions are comparable, both reaching approximately 30%. These results provide a physics-based, experimentally validated framework for understanding defect-transport coupling in irradiated rock-salt nitrides and provide broader insight into radiation-tolerant materials with mixed electron-phonon thermal transport.