Direct and complete electro‐oxidation of ethanol to CO₂ is highly desirable for the commercialization of the direct ethanol fuel cells but is challenging. Current electrocatalysts (mainly Pt, Pd) for ethanol oxidation reaction (EOR), unfortunately, still suffer from low CO₂ selectivity and rapid performance deterioration. In this study, a new Pt/α‐PtO_x/WO₃ electrocatalyst containing amorphous PtO_x structures is successfully synthesized via a facile hydrothermal reaction following Ar atmosphere annealing. The migration of lattice oxygens in the WO₃ during the annealing process is confirmed as the mechanism for the formation and manipulation of amorphous interfaces containing PtO_x species in the Pt/α‐PtO_x/WO₃ electrocatalyst. The obtained Pt/α‐PtO_x/WO₃ with tunable amorphous PtO_x interfaces favors the desorption of poisoning EOR intermediates (such as CO) and high CO₂ selectivity. Therefore, the state‐of‐art of the Pt/α‐PtO_x/WO₃ exhibits excellent EOR activity (2.76 A mg^–1), stability (47.99% of the initial activity preserved after 3600 s), and particularly high CO₂ selectivity (reached 21.9%, higher than most reported values for Pt or other noble metals based EOR catalysts). This study may provide a new strategy to improve the EOR performance of metal‐based catalysts and to rationally design and prepare other high‐performing electrocatalysts via engineering the amorphous interfaces.