Somdet Ong Pathom 21 Sok is a  large Buddhist shrine in the tambon Tha Kanun of Thong Pha Phum District, in Kanchanaburi Province, located at the beginning of the National Road 323 to Sangkhlaburi.

Towards the end of the road, into this border town with Myanmar, is a similar —yet smaller— roadside shrine (fig.), that belongs to Sangkhlaburi's Wat Somdet (fig.). Since 1 sok is 50 centimeter, its name suggests that the principal Buddha image is 10.5 meter tall.

Somdet Ong Pathom 21 Sok features a giant white Buddha image on an elevated platform, flanked on either side by a large open sala-like hall each of which contains a row of 17 gilded Buddha images, all seated in the maravijaya pose.