Although the catalytic oxidative dehydrogenation of ethane (ODE) to ethene has not reached a stage of industralization, there are recent progresses that are rather encouraging. The aim of future research is to generate a catalyst that can achieve high ethene selectivity and high ethane conversion; it is also critical to minimize side reactions and coke formation. Up to now, a vast number of materials with different catalytic behaviors have been tested as ODE catalysts. In this review, we divide the catalysts reported in the literature in the past three decades into six classes, viz. (i) alkaline earth metal-based oxides, (ii) transition metal-based oxides, and (iii) rare earth metal-based oxides, (iv) perovskite-type and related oxides, (v) supported noble metals, and (vi) others. The activation of reactants and structural defects of the catalysts have been examined with an attempt to clarify the relation between reactant activation and defective structures. The reactivities of various oxygen species towards ethane and ethene have been discussed as well. By modifying a catalyst with a suitable promoter, one can facilitate the activation processes and manipulate the nature and concentration of active oxygen for better catalytic performance. We have also touched briefly on the catalytic dehydrogenation of ethane with oxidants such as N₂O and CO₂. As for reaction mechanism, we have highlighted the heterogeneous-homogeneous and redox (Mars-van Krevelen) behaviors of these catalytic materials.