Huai Kha (Thai: ห้วยข่า) is a tambon (subdistrict) located in the northwestern region of Buntharik district, in Ubon Ratchathani Province, Thailand.

[1] Neighbouring subdistricts are (clockwise from the west) Na Chaluai, Sok Saeng, Non Kho, and Phon Ngam, as well as Soukhoumma and Mounlapamok districts of Laos in the east and south.

The first settlement was named "Huai Kha," after Alpinia galanga, which was found numerously in the region, especially in the waterside area; Huai ห้วย means "stream, creek, brook," and Kha ข่า refers to "Alpinia galanga".

[2] Huai Kha was one of the three oldest subdistricts (tambon) of the Buntharik district, together with Phon Ngam and Kho Laen.

The northwest area, one-third of the total, is an undulating plateau where most of its population settled, while the remaining area is a rolling plain and highland of the Dângrêk Mountains, which form the border between Thailand and Laos.