William McWillie (November 17, 1795 – March 3, 1869) was the twenty-second governor of Mississippi from 1857 to 1859.

He was born near Liberty Hill, Kershaw County, South Carolina, on November 17, 1795.

He was elected to the United States House of Representatives in 1849, serving from December 3, 1849 to March 3, 1851.

McWillie died in Kirkwood, Madison County, Mississippi, on March 3, 1869.

[4][5] His son Adam McWillie (1821 to 1861) was killed in the Civil War during the First Battle of Bull Run.