William Arthur McKeighan (January 19, 1842 – December 15, 1895) was an American politician.

He enlisted in the 11th Regiment Illinois Volunteer Cavalry, in September 1861, to fight in the Civil War.

McKeighan started to take interest in creating the Farmers' Alliance and was elected Probate Judge of Webster County from 1885 to 1887.

Following the results of the 1890 census being apportioned, McKeighan ran for the newly created 5th district in 1892 and won again.

He ran and lost for reelection in 1894, and died in Hastings, Nebraska, on December 15, 1895.