Leintz-Gatzaga is a town and municipality in the province of Gipuzkoa, part of the Autonomous Community of the Basque Country in northern Spain. It is a small settlement, with a population recorded as 251 in 2015.
The town lies in the mountainous interior of Gipuzkoa, near the border with the province of Álava. Its name reflects a long association with salt: "gatzaga" means saltworks or salt pan in Basque, and salt production was historically the defining activity of the locality.