This is the first review of titanium dioxide-zirconium dioxide (TiO2-ZrO2) mixed oxides, which are frequently employed as catalysts and catalyst supports. In this review many details pertaining to the synthesis of these mixed oxides by various conventional and nonconventional methods and their characterization by several techniques, as reported in the literature, are assessed. These mixed oxides have been synthesized by different preparative analogies and were extensively characterized by employing various spectroscopic and nonspectroseopic techniques. The TiO2-ZrO2 mixed oxides are also extensively used as supports with metals, nonmetals, and metal oxides for various catalytic applications. These supported catalysts have also been thoroughly investigated by different techniques. The influence of TiO2-ZrO2 on the dispersion and surface structure of the supported active components as examined by various techniques in the literature has been contemplated. A variety of reactions catalyzed by TiO2-ZrO2 and supported titania-zirconia mixed oxides, namely; dehydrogenation, decomposition of chlorofluoro carbons (CFCs), alcohols from epoxides, synthesis of ε-caprolactam, partial oxidation, deep oxidation, hydrogenation, hydroprocessing, organic transformations, NOx abatement, and photo catalytic VOC oxidations that have been pursued in the literature are presented with relevant references.