William Sydney Wilson (November 7, 1816 - November 3, 1862) was a prominent Confederate politician. He was born in Worcester County, Maryland and later moved to Mississippi. He was the son of Ephraim King Wilson and brother to Ephraim King Wilson II. Member of the Mississippi state legislature 1858 to 1859 and 1860 to 1861. Represented the state in the Provisional Confederate Congress from February 4, 1861 to March 16, 1861. He later joined the Confederate Army and was mortally wounded at the Battle of Antietam.