Nachikatsuura is a town located in Higashimuro District, Wakayama Prefecture, Japan. As of February 1, 2012, the town has an estimated population of 17,261, with 8,359 households, and a density of 94.09 persons per km². The total area is 183.45 km².
Created in 1955 from four towns: Nachi, Katsuura, Ukuimura and Wakamura, by 1960 the municipality expanded to include Shimosato farther south and Otamura inland up the Ota River.
The Kumano Nachi Taisha, one of the three Kumano Shrines, is in Nachi Katsuura. These shrines form part of the "Sacred Sites and Pilgrimage Routes in the Kii Mountain Range" UNESCO World Heritage Site.