Dok Khamtai (Thai: ดอกคำใต้, pronounced [dɔ̀ːk kʰām.tâːj]) is a district (amphoe) of Phayao province in northern Thailand.

[3] Dok Khamtai is the Thai name of the sponge tree (Acacia farnesiana (L.) Willd.).

[citation needed] The district is "...famous in Thailand for the numbers of sex workers it exports and there is even a popular song titled 'plaeng saaw dok kham tai' ('song of the young women from Dok Khamtai') about girls from this district coming to Bangkok."

The district is also mentioned prominently in Pasuk Phongpaichit's 1982 study, From Peasant Girls to Bangkok Masseuses.

[4] The district is divided into 12 sub-districts (tambons), which are further subdivided into 124 villages (mubans).