Allylic oxidations of olefins to enones are C-H functionalizations and are valuable organic transformations that permit the synthesis of value-added products from simple precursors. A variety of stoichiometric and catalytic metal-based methods are available for these conversions. In addition, metal-free and biocatalytic protocols are gaining in importance. This review summarizes the available oxidation methods and compares their regio- and chemoselectivities. 1Introduction 2Chromium-Based Oxidation 2.1Stoichiometric Methods 2.2Catalytic Methods 2.3Chromium on Solid Support 3Regio- and Chemoselectivity of Allylic Oxidations 4Other Metal-Based Oxidations 4.1Copper Reagents 4.2Rhodium Reagents 4.3Selenium Reagents 4.4Cobalt Reagents 4.5Ruthenium Reagents 4.6Palladium Reagents 4.7Iron Reagents 4.8Other Metal Reagents 5Metal-Free and Biocatalytic Methods 5.1Metal-Free Methods 5.2Biocatalytic Methods 6Conclusion