We report graphene nanoplatelets (GNPs), which exhibit the advantages of both single-layer graphene and highly graphitic carbon, as a durable alternative support material for Pt nanoparticles for oxygen reduction in fuel cells. Pt nanoparticles are deposited on poly(diallyldimethylammonium chloride) (PDDA)-coated GNP, and characterized with transmission electron microscopy, X-ray diffraction, Raman spectra, and electrochemical tests. Pt/GNP exhibits greatly enhanced electrochemical durability (2–3 times that of Pt/CNT and commercial Etek Pt/C). These are attributed to the intrinsic high graphitization degree of GNP and the enhanced Pt-carbon interaction in Pt/GNP. If considering that GNP can be easily mass produced from graphite, GNP is a promising, low-cost, and durable electrocatalyst support for oxygen reduction in fuel cells.