The controllable synthesis of nanostructured CeO₂-based materials is an imperative issue for environment- and energy-related applications. In this review, we present the recent technological and theoretical advances related to the CeO₂-based nanomaterials, with a focus on the synthesis from one dimensional to mesoporous ceria as well as the properties from defect chemistry to nano-size effects. Seven extensively studied aspects regarding the applications of nanostructured ceria-based materials are selectively surveyed as well. New experimental approaches have been demonstrated with an atomic scale resolution characterization. Density functional theory (DFT) calculations can provide insight into the rational design of highly reactive catalysts and understanding of the interactions between the noble metal and ceria support. Achieving desired morphologies with designed crystal facets and oxygen vacancy clusters in ceria via controlled synthesis process is quite important for highly active catalysts. Finally, remarks on the challenges and perspectives on this exciting field are proposed.