In this study, reduced forward voltage and improved light output power of GaN-based vertical light-emitting diodes (VLEDs) incorporating single-walled carbon nanotube (SWNT)-networks is reported. The SWNT-networks were directly formed on a roughened (textured) n-GaN surface via a solution-processed dip-coating method. The surface-roughened VLEDs with the proposed SWNT-networks had a forward voltage of 3.84 V at 350 mA, lower than that of the surface-roughened VLEDs, and exhibited an increase in light output power by 12.9% at 350 mA compared to the surface-roughened VLEDs. These improved electrical and optical properties could be attributed to the SWNT-networks put on the roughened n-GaN surface, which increase the lateral current transport and create scattering of light through the formation of additional roughness.