Thenmarachchi is one of the three historic regions of the Jaffna peninsula in northern Sri Lanka.

Thenmarachchi is sometimes spelt Thenmarachi, Thenmaraachi or Thenmaraadchi.

This area, like the entire Jaffna peninsula, is populated mostly by Tamil people and was for many years under the de facto control of the "Tamil Tigers".

It is derived from the Tamil words thenmar (southerners) and achchi (possession or rule).

This Northern Province, Sri Lanka location article is a stub.