Vex (Arpitan: Vés) is a municipality and capital of the district of Hérens in the canton of Valais in Switzerland .

Vex has an area, as of 2009, of 13 square kilometers (5.0 sq mi). Of this area, 4.17 km2 (1.61 sq mi) or 32.1% is used for agricultural purposes, while 6.17 km2 (2.38 sq mi) or 47.5% is forested. Of the rest of the land, 1.71 km2 (0.66 sq mi) or 13.2% is settled (buildings or roads), 0.07 km2 (17 acres) or 0.5% is either rivers or lakes and 0.87 km2 (0.34 sq mi) or 6.7% is unproductive land.

Of the built up area, housing and buildings made up 7.2% and transportation infrastructure made up 4.8%. Out of the forested land, 38.6% of the total land area is heavily forested and 7.7% is covered with orchards or small clusters of trees.