Diamond and diamond devices are potentially radiation damage resistant due to diamond’s wide bandgap and high displacement energy per atom. Conducting channels in diamond—necessary for the realization of field effect transistors (FETs)—are based on hydrogen-terminated surfaces or buried implanted acceptors (delta doping). The present thesis investigates the susceptibility of these channels to either ionizing or non-ionizing radiation. Gamma radiation tolerances of H-terminated based FETs at low (≤100 krad) and high doses up to 26 Mrad, and proton radiation tolerance of H-terminated and delta doped substrates at 152 keV and fluences of 1.02 x1012 cm-2 are studied. For gamma radiation, we report a decrease in drain current and threshold voltage for low dose but increase in both at high dose. And for proton radiation, we report a change in activation energy for conductivity, an increase in resistivity, and a decrease in both mobility and carrier concentration.