Saen Hai (Thai: แสนไห, pronounced [sɛ̌ːn hǎj]) is a tambon (subdistrict) of Wiang Haeng District, in Chiang Mai Province, Thailand.

Its name comes from "Phra Borom That Saen Hai", a local ancient cetiya (indeed, it lies in the adjoining area Mueang Haeng).

According to the local legend, King Naresuan rested his armies here and built a pool at the foot of the hill for his use and that of his war elephants.

The terrain is shaped like a plow along the length of north to south, with a total area of approximately 22 km2 (13,750 rai).

Saen Hai is about 5 km (3 mi) from Wiang Haeng District Office via Mae Cha–Piang Luang Road.