A process based on sputtering has been developed for fabricating thin-film solid oxide fuel cells (TF-SOFCs) that have a total thickness of ~3 µm and are based on the conventional configuration using common SOFC materials. Single cells (with dense electrolytes, dense interlayers, and porous electrode films) on various substrates were effectively fabricated through sputtering/co-sputtering of metal and/or ceramic targets and the electrodes exhibited a fine nanostructure consisting of very small columns of roughly 10 nm in diameter. Fabricated cells exhibit open circuit voltages of ~1.0 V and exceptional power densities at reduced temperatures (500^o-650^oC) on different fuels. Single cells (of the composition lanthanum strontium cobaltite-gadolinium doped ceria (LSC-GDC) cathode/GDC interlayer/yttria stabilized zirconia (YSZ) electrolyte/Ni-GDC anode) show record power densities of ~3.5 W/cm² with hydrogen/air and ~1.5 W/cm² with dry methane/air at 650^oC.