An oxidative desulfurization process is provided in which gaseous oxidant required for oxidative desulfurization reactions is dissolved in the feedstock upstream of the oxidative desulfurization reactor. Gaseous oxidant is mixed with a generally liquid phase feedstock (and in certain embodiment peroxide precursors are also mixed) in a mixing zone under conditions effective to dissolve the gaseous oxidant in the liquid feedstock. The gaseous oxidant dissolved in the hydrocarbon feedstock provides a gaseous oxidant-enhanced feedstock which is charged to the oxidative desulfurization reaction zone thereby permitting substantially liquid phase operation.