To enhance the mechanical properties of molybdenum alloys at both room and high temperatures, Mo-14Re-1CeO2 alloy was synthesized using the powder metallurgy method, and the corresponding microstructure and mechanical properties were characterized. The results indicate that the ultimate tensile strength of Mo-14Re-1CeO2 reaches 657 MPa, with a total elongation of 35.2%, significantly higher than those of pure molybdenum (453 MPa, and 7.01%). Furthermore, the compression strength of Mo-14Re-1CeO2 at high temperature (1200 °C) achieves 355 MPa, which is still larger than that of pure molybdenum (221 MPa). It is revealed that there is a coherent interface between CeO2 and the Mo-14Re matrix with CeO2 particles uniformly distributed in both intergranular and intragranular regions. The improvements in mechanical properties are primarily attributed to the formation of Mo-Re solid solution, grain refinement, and dispersion strengthening effect of CeO2.