We have examined the chemisorption and reaction of NO and N2O on ceria surfaces by soft X-ray photoelectron spectroscopy (SXPS), X-ray absorption spectroscopy, and isothermal and temperature programmed desorption (TPD) spectroscopy. Samples include highly oriented CeO2(100) and CeO2(111) thin films with surfaces of variable oxidation states. CeO2(111) thin films were grown in situ allowing control over the initial oxidation state of the ceria surface, quantitatively determined by valence band, Ce 4d, and Ce 3d photoemission. Following NO exposure, various N-containing surface species were observed by N 1s photoemission, and the distribution of these species depended upon surface oxidation state, exposure, and adsorption temperature. These species included N2O, nitrite, NO-, and three states believed to be associated with atomic or anionic forms of N, Nitrite and N2O are seen on a fully oxidized surface while NO-, N2O, and dissociation products are observed on a reduced surface. The primary reaction of NO with reduced ceria is reoxidation of the ceria by the NO, both by NO-formation and by NO dissociation, leading to immediate and thermally induced N-2 desorption. Adsorption of NO at 150 K is predominantly molecular while exposure to NO at 400 K leads to a thermally activated nitride which desorbs at temperatures above 500 K. Dissociative adsorption of NO leads to the displacement of N3- at high exposures.