Mukdahan (มุกดาหาร) is a city and province in Isaan.
Mukdahan is the 73rd province of Thailand. Its history dates from the late Ayutthaya period, over 200 years ago. At first, on the left side of the Mekong River, there was a large community called Ban Luang Phon Sin located by Phrathat Ing Hang, now in Savannakhet Province of Lao PDR. The community was ruled by Chao Chan Suriyawong. His son was Chao Kinnari. He later built a new town at the mouth of Huai Muk on the right bank of the Mekong River in 1767. The town was completed in 1770 and named "Mukdahan" (moonstone or pearl) according to a propitious sign occurring to him while the town was under construction. That is why the locals call the town "Mueang Muk".