Wat Thatnoi (GPS: 18.74792, 99.00079; Thai: วัดธาตุน้อย ) is the preserved ruins of a Thai Buddhist monastery in Wiang Kum Kam, to the south of Chiang Mai, Thailand. What's left today are the remains of what the monastery once was, sitting on a brick base.
There are no historical record of Wat Thatnoi. The name "thatnoi" means "little chedi". Until restoration work was carried out, the monastery was buried in soil of 60-70 centimeters deep. Based on its architecture, archaeologists have determined that this monastery dates from the 14th or 15th century.