Wallowa County () is one of the 36 counties in the U.S. state of Oregon. As of the 2010 census, the population was 7,008, making it Oregon's fourth-least populous county. Its county seat is Enterprise. According to "Oregon Geographic Names", the origins of the county's name are uncertain, with the most likely explanation being it is derived from the Nez Perce term for a structure of stakes (a weir) used in fishing. An alternative explanation is that "Wallowa" is derived from a Nez Perce word for "winding water". The journals of Lewis and Clark Expedition record the name of the Wallowa River as "Wil-le-wah".