Uniform and porous graphene nanoﬂake ﬁlms (GNFs) have been investigated as a support for catalytic Pt nanoclusters in direct methanol electro-oxidation. Pt nanoclusters of varying thickness are deposited on GNFs using magnetron sputtering, and their effects on the electrocatalytic activity for oxidizing methanol are systemically studied. GNF supported Pt nanoclusters with ultralow catalyst loading exhibit high performance for methanol electrocatalytic oxidation with a large mass-speciﬁc peak current density and a ratio of forward to backward peak currents up to 1.4. These characteristics compare favorably to the majority of Pt C based electrodes, except for those of carbon nanotubes with Pt decoration on both the inner and the outer wall surfaces. The results obtained are ascribed to a highly coupled network made of high-density 2 4nmPt monolayer nanoclusters on both the basal and edge planes of each nanoﬂakes of graphene. GNFs are a promising support material for developing next-generation advanced Pt based fuel cells and their relevant electrodes in the ﬁeld of energy.