A deep level transient spectroscopy study of proton irradiation induced defects in n+p InP mesa diodes grown by metalorganic chemical vapor deposition is reported. In contrast to results reported for InP grown by other methods, 3 MeV proton irradiation produced a DLTS spectrum similar to 1 MeV electron irradiation with the addition of two new peaks. Six majority carrier peaks: HP1(Ea=0.15 eV), H2(Ea=0.20 eV), H3(Ea=0.30 eV), H4(Ea=0.37 eV), H5(Ea=0.54 eV), and H7(Ea=0.61 eV) and three minority carrier peaks: EA(Ea=0.26 eV), EB(Ea=0.74 eV), and EC(Ea=0.16 eV) were detected. The H5 peak displayed a thermally activated capture cross section and a dependence of peak height on injection level. Isothermal annealing at 375 K was performed and thermal annealing rates are presented. Low temperature (200 K), minority carrier injection annealing rates are also presented. For most of the defects, a significant residual concentration remained after injection which could not be annealed further. An equation was developed for the annealing rate of the major defect, H4, as a function of injection level, carrier concentration, and temperature.