William Elsey Connelley (March 15, 1855[1] - July 15, 1930) was an American writer, historian and school teacher.

He is best known for a series of books that document the history of Kansas, the Civil War, and the United States in the 19th and early 20th centuries.

[2] In the 1890s Connelley became interested in a hobby of historical research, and in the subsequent years, he published a number of non-fiction books about history.

Some of his most important books were The Provisional Government of Nebraska Territory (1899), Quantrill and the Border Wars (1909), Eastern Kentucky Papers (1910), Life of Preston Plumb (1913), a five volume History of Kansas (1917), a five volume History of Kentucky (1922) and Indian Myths (1928).

Connelley's books were full of details and included much material obtained in interviews with persons present at historical situations about which the author wrote.