Saillon (French pronunciation: [sajɔ̃]; Arpitan: Salyon) is a municipality in the district of Martigny in the canton of Valais in Switzerland .

Saillon is first mentioned in 1052 as castellum Psallionis. The municipality was formerly known by its German name Schellon, however, that name is no longer used.

Saillon has an area, as of 2009, of 13.7 square kilometers (5.3 sq mi). Of this area, 5.17 km2 (2.00 sq mi) or 37.6% is used for agricultural purposes, while 2.81 km2 (1.08 sq mi) or 20.5% is forested. Of the rest of the land, 1.12 km2 (0.43 sq mi) or 8.2% is settled (buildings or roads), 0.31 km2 (0.12 sq mi) or 2.3% is either rivers or lakes and 4.27 km2 (1.65 sq mi) or 31.1% is unproductive land.