Robert Vaughn (born Robert Vaughan; June 5, 1836 – March 23, 1918) was a Welsh immigrant to the United States and an important rancher, farmer, and businessman in the U.S. state of Montana during the years before and after its statehood. He homesteaded the Vaughn ranch in the Sun River valley in Montana, building a sandstone mansion as his home there. The town of Vaughn, Montana, is named in his honor. He also helped co-found the city of Great Falls, where he built the Arvon Block, a hotel and stable and one of the city's earliest buildings; the ranch and the hotel are both listed on the National Register of Historic Places.