Organic light-emitting devices (OLEDs) were fabricated utilizing a poly(4-butylphenyl-diphenyl-amine) (poly-TPD):dodecanethiol functionalized Au (DDT-Au) nanocomposite (NC) layer to enhance their current efficiency. The photoluminescence intensity of the poly-TPD:DDT-Au NC film at 514 nm was significantly increased, being about 1.3 times that of the poly-TPD film due to the coupling between the excitons in the emitting layer and the localized surface plasmonic resonance of the DDT-Au nanoparticles. The current efficiency of the green OLEDs with a poly-TPD:DDT-Au NC layer at 1000 cd/m2 was 3.1 cd/A larger than that with a poly-TPD layer, resulting in an enhanced out-coupling efficiency due to the coupling effect.