Khammouane province (Khammouan) is a province in the center of Laos. Its capital lies at Thakhek.

Thakhek, the capital of Khammouane Province, is a town in south-central Laos on the Mekong River and the administrative centre of the district with the same name. The Third Thai–Lao Friendship Bridge, linking Thakhek and Nakhon Phanom, Thailand, across the river, started in 2009 and was opened on 11 November 2011.