Khlung (Thai: ขลุง, pronounced [kʰlǔŋ]) is the southernmost district (amphoe) of Chanthaburi province, eastern Thailand.

Neighboring districts are (from the northwest clockwise) Laem Sing, Mueang Chanthaburi, Makham, Pong Nam Ron of Chanthaburi Province, Bo Rai, Khao Saming, and Laem Ngop of Trat province.

The district is divided into 12 sub-districts (tambons), which are further subdivided into 90 villages (mubans).

There are a further 11 tambon administrative organizations (TAO).

This Chanthaburi Province location article is a stub.