Backgrounds: Approximately 18 million individuals were diagnosed with cancer in 2018. The rate is predicted to exceed 22 million by 2030. Radiotherapy is an essential part of cancer therapy, with well documented local and systemic side effects, including oxidative stress and apoptosis. Kidney tissues are also exposed to the deleterious effects of radiotherapy, resulting in acute or chronic kidney function impairment. This study compared the effects of the potent selective α2-adrenoreceptor agonist dexmedetomidine and amifostine on oxidative stress and apoptosis in kidney damage induced by x-irradiation in rats. Methods: Forty Sprague Dawley rats were assigned into five groups: control, x-irradiation, x-irradiation + amifostine, x-irradiation + dexmedetomidine 100 µg/kg, and X-ray irradiation + dexmedetomidine 200 µg/kg. Results: Necrotic tubules and degenerative Bowman’s capsules were present in the x-irradiation group. An increase was determined in malondialdehyde (MDA), Cleaved Caspase-3, and 8-OHdG levels compared to the control group (p ≤ 0.05). In contrast, there was a decrease in necrotic tubules, degenerative Bowman’s capsules, and the levels of MDA, Cleaved Caspase-3, and 8-OHdG in the amifostine and dexmedetomidine 100 µg/kg and 200 µg/kg treatment groups (p ≤ 0.05). Conclusions: Alpha 2 adrenergic receptor agonists exhibit protective effects against kidney injury induced in association with x-irradiation by reducing oxidative stress and apoptosis.