Mae Sariang Subdistrict () is a sub-district (tambon) of Mae Sariang District, in Mae Hong Son Province, Thailand. In 2005 it had a population of 9,968 people. The tambon contains nine villages.
Parts of sub-district Mae Sariang and of neighboring Ban Kat Sub-district form the Mae Sariang Sub-district Municipality.
Mae Sariang lies in the valley of the Yuam River, which runs through the town from north to south. While the town itself is at an elevation of , the land rises much higher just to the east in the Thanon Thong Chai Range, with hills beside the city reaching over .
Mae Sariang has a tropical savanna climate (Köppen climate classification Aw). Winters are dry and warm. Temperatures rise until April, which is very hot with the average daily maximum at . The monsoon season runs from May through October, with heavy rain and somewhat cooler temperatures during the day, although nights remain warm.
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Mae Sariang is connected to the rest of Thailand by two main roads: Route 108, which enters Mae Sariang from the east (from Chiang Mai) and exits to the north (to Mae Hong Son); and Route 105, which leads south out of the town through Mae Sot to Mueang Tak.
Mae Sariang is served by Mae Sariang Airport.