Plasmonic nanostructures with large absorption areas under resonant excitation have been utilized extensively in photon‐assisted applications. In this work, dodecahedral Au nanobowls were first prepared by an easy and template‐free method only through the introduction of H2PtCl6 and I− during the growth procedure. The Au nanobowls show electron‐field enhancement due to the high curvature of the bowl edge, the open region, and dodecahedral morphology. Au/Pt nanobowls, which couple plasmonic Au and catalytic Pt, were then constructed as plasmonic electrocatalysts for methanol oxidation. The mass activity reached 497.6 mA mg−1 under visible‐light illumination, which is 1.9 times that measured in the dark. Simultaneously, the electrocatalytic stability is also greatly improved under light excitation. The enhanced properties of the plasmonic Au/Pt electrocatalysts are ascribed to the synergistic effect of the plasmon‐enhanced photothermal and hot‐carrier effects on the basis of experimental investigations. This work thus offers an effective methodology to construct efficient plasmonic electrocatalysts for fuel cells. [ABSTRACT FROM AUTHOR]