An innovative approach for the high-throughput, rapid, and low-cost fabrication of ultranarrow graphene nanoribbons (GNRs) using nanosphere lithography (NSL) nanopatterning in combination with low-power O-2 plasma etching is presented. The intrinsic simplicity of NSL patterning enables this fabrication approach to be applicable for the straightforward on-chip fabrication of GNRs and bandgap tuning of graphene.