Chan Sen, also written as Chansen (Thai: จันเสน, pronounced [t͡ɕān.sěːn]) is a tambon (subdistrict) in Takhli District, Nakhon Sawan Province, upper central Thailand.

Chan Sen's history dates back more than 2,000–3,000 years and is considered an ancient town in the late Iron Age and continued until the early Dvaravati period, contemporary with Funan in present-day Vietnam and Suphan Buri's U Thong.

This is confirmed by the discovery of human skeletons, fragments of pottery, stone axes and iron tools on Khao Chong Khae Hill in the area and at Ban Mai Chaimongkol Village in its district as well as the neighbouring areas.

The condition of the ancient town of Chan Sen was first discovered from aerial photographs in 1966 by Thai architect and national artist Nij Hincheerana.

[1] In addition, Chan Sen used to be an important trading route in the Lop Buri–Pasak basin.