Si Thep, also Sri Thep, (7th ??14th century CE) is an ancient ruined town in Northeast Thailand. Many architectural structures still remain to indicate its past prosperity. It was once the centre of contact between the Dvaravati Kingdom in the central plain basin of Thailand and the Khmer Kingdom in the Northeast.

A twin- city, there were over one hundred ancient sites all built with bricks and laterite. There are also remains of several ponds spread out all over the area. Most of the ancient relics recovered are architectural by nature such as elaborate lintels and sema stones. A few of the human skeletons discovered are still adorned with ornamental pieces.