The area of Oklahoma known as No Man's Land was a strip of land 34 miles wide that ran along the western border of Oklahoma and extended from the northwestern corner of the state to the southern border with Texas.

This area was called No Man's Land because it was not officially assigned to any state or territory after the Indian Territory was opened to settlement. It was unorganized and lawless, attracting outlaws and adventurers.

It was finally annexed by Oklahoma in 1907 and is now part of Cimarron County, the westernmost county in the state.