Foss is a town in Washita County, Oklahoma, United States. At one time the town had a population of nearly 1000 residents. During World War II, the town boasted a population of over 300 residents, relying primarily on Route 66 travellers (which passed half a mile south of the city) and a U.S. naval base south of the town that operated during wartime. A gas station and a café also operated in the town around that time. The population was 127 at the 2000 census. Today, though still incorporated, Foss is considered to be a ghost town.

The history of Foss began when settlers from the area of the Wilson post office moved four miles north to the valley of Turkey Creek in the late 1890s. They initially wanted their new post office to be called Graham, but since that name was already taken it was named Maharg. A flash flood on May 2, 1902 wiped out the town on Turkey Creek, destroying businesses and drowning several people. The town rebuilt on higher ground and was named Foss. The post office began operation on September 15, 1900.
The town expanded rapidly. By 1905 the town had a population between 900 and 1000 residents. It boasted two banks, three cotton gins, and by 1912 had an electric plant, two hotels and an opera house. The population stabilized near 500. In the 1920s the town began to have problems and the nearby cities of Clinton and Elk City absorbed more and more trade.

During the Great Depression more people moved away, though in the 1950s and 1960s there was an economic revival due to the nearby Air Force installation at Burns Flat. When the base closed and Interstate 40 bypassed Foss the town declined further. The last bank left in September 1977.

Today mostly foundations and sidewalks are all that is left of Foss. A church built in 1894 and a pioneer jail still stand.

Foss had two newspapers, the Foss Enterprise and the Foss Banner. It was served by the Choctaw, Oklahoma and Gulf Railroad (Rock Island) railroad.