Unique tin oxide-mesoporous carbon (SnO2-CMK-3) composites have been synthesized as platinum nanoparticle electrocatalyst supports for low temperature fuel cell applications. In comparison with state-of-the-art commercial carbon-supported platinum (Pt/C) and pure CMK-3-supported platinum (Pt/CMK-3), Pt/SnO2-CMK3 demonstrated improved Pt-mass and surface area based ethanol oxidation reaction (EOR) activity through half-cell electrochemical investigations, providing a 64.7 and 97.6 mV reduction in overpotential at 100 mA mg(Pt)(-1) upon comparison to Pt/CMK-3 and commercial Pt/C. Furthermore, improvements to the oxygen reduction reaction (ORR) kinetics were observed, with Pt/SnO2-CMK3 providing a kinetic current density of 3.40 mAcm(-2) at an electrode potential of 0.9 V vs RHE. The improved performance of Pt/SnO2-CMK-3 for EOR and ORR was attributed to the beneficial impact of the support properties, along with potential interactions occurring between the support and catalyst particles. Complemented by extensive physicochemical characterization, these unique materials show high promise for application in low temperature fuel cells.