Abstract: A process for producing olefins comprising introducing to a reactor a reactant mixture comprising methane, oxygen, and water, wherein the reactor comprises a catalyst, and wherein water is present in the reactant mixture from 0.5 mol % to 20 mol %; allowing the reactant mixture to contact the catalyst and react via an OCM reaction to form a product mixture comprising C2+ hydrocarbons, unreacted methane, and byproducts; wherein C2+ hydrocarbons comprise olefins and paraffins; and wherein the process is characterized by a productivity, a C2+ selectivity, or both that is increased when compared to a productivity, a C2+ selectivity, or both, respectively, of an otherwise similar process conducted (i) with a reactant mixture comprising methane and oxygen and (ii) without water present in the reactant mixture from 0.5 mol % to 20 mol %; recovering the product mixture from the reactor; recovering C2+ hydrocarbons from the product mixture; and recovering olefins from C2+ hydrocarbons.