Wiltshire-Butler National Park was created as Class A reserve No. 47667 on 30 November 2004 with a size of 11,645 hectares (28,780 acres) as one of nine national parks proclaimed in the state that day.[4][5]
The national park was named after John Francis Wiltshire-Butler, a former employee of the Forests Department, who died fighting a bushfire at Barlee Brook in 1958. The Hilliger National Park, further to the south-east, was named Johannes Hilliger for the same reason, having also died fighting the 1958 fire.[6]