Dry reforming of methane via the nonstoichiometric ceria (CeO2 - CeO2-δ) redox cycle was theoretically and experimentally examined for converting high-temperature, solar process heat to syngas. This cycle is composed of: (1) endothermic reduction of ceria and simultaneous partial oxidation of methane and (2) exothermic oxidation of the reduced ceria and simultaneous reduction of carbon dioxide. In both steps, chemical equilibrium calculations indicate that isothermal operation is thermodynamically favorable under a wide range of conditions. The influence of the total amount of reactive gas, operating temperature, and inclusion of gas/solid phase heat exchangers on cycle performance was determined through a holistic process model. A solar-to-fuel conversion efficiency, defined as the ratio of the difference between the calorific value of syngas (H2 and CO) produced and CH4 converted to the total solar radiative input energy, greater than 45 % was theoretically predicted with no heat recuperation. Experimental validation was subsequently demonstrated in a packed bed type solar reactor using the high flux solar simulator at the University of Florida at three discrete isothermal temperatures: 950 °C, 1035 °C, and 1120 °C. Upon completion of reduction at each temperature, bed-averaged oxygen nonstoichiometry equaled 0.07, 0.21, and 0.24, yielding methane conversions of 9, 41, and 51 % respectively. At 1120 °C, the extrapolated solar-to-fuel conversion efficiency equaled 9.82 %.