Unicoi is located at (36.220028, -82.338138). The town is situated in the North Indian Creek Valley (known locally as "The Valley Beautiful"), at a point where North Indian Creek emerges from the mountains to the southeast and bends to the southwest toward Erwin and its eventual confluence with the Nolichucky River. The northern portions of Unicoi are located in the headwaters of Buffalo Creek, which flows northeastward (in the opposite direction from North Indian Creek) and eventually empties into the Watauga River.