William Sydney Wilson (November 7, 1816 – November 3, 1862) was an American politician.
He was born in Snow Hill, Maryland, and later moved to Mississippi. He was the son of Ephraim King Wilson and brother to Ephraim King Wilson II. He was a member of the Mississippi State Legislature from 1858 to 1859 and 1860 to 1861. He represented the state in the Provisional Congress of the Confederate States from February 4, 1861, to March 16, 1861. He later joined the Confederate States Army and was mortally wounded at the Battle of Antietam.[1]