AbstractCeria nanoparticles with 4 and 7 atom‐% manganese dopant were synthesized through a template‐free solvothermal method. The structure of the samples was characterized by powder X‐ray diffraction (XRD). Monodispersed nanospheres of average size 130 nm were observed in transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), and field‐emission scanning electron microscopy (FE‐SEM) analyses. Manganese ions were introduced into the system and it is confirmed that the Mn species dissolve within the CeO2 lattice by Raman spectroscopy and X‐ray photoelectron spectroscopy (XPS). Furthermore, the as‐obtained Mn‐doped ceria nanoparticles revealed superior catalytic performance in CO oxidation in contrast with pure CeO2 prepared by the same route.