Electrocatalytic conversion of methane (CH4) to valuable chemicals under mild conditions is an attractive approach that combines the direct utilization of natural gas as a hydrocarbon feedstock and the chemical storage of renewable electricity. However, it remains a great challenge due to the intrinsic chemical inertness of CH4. Here we report that a NiO/Ni interface constructed by calcination can act as the active site for the electrooxidation of CH4 to alcohols especially ethanol. With the optimized NiO/Ni interface catalyst, an 89 % Faradaic efficiency (FE) for ethanol production with a yield of 25 μmol∙gNiO−1∙h−1 at 1.40 V versus reversible hydrogen electrode (RHE) was achieved. Experiments and density functional theory (DFT) calculations demonstrated that the NiO/Ni interface enables efficient C–H activation and C–C coupling, leading to the highly selective formation of ethanol from CH4 electrooxidation.