Alexander Stuart Wallace (December 30, 1810 – June 27, 1893) was a United States Representative from South Carolina.

The son of American colonial immigrant McCasland Wallace (born at sea on the Atlantic Ocean to a Scots-Irish family on their way to the port of Charleston, South Carolina), Wallace was born near York, South Carolina and received limited schooling.

Wallace quietly refrained from supporting the Confederacy in any way during the war years, though this was a situation he had to navigate carefully, as his earlier Unionist sympathies made him a target.

South Carolina's 1868 Constitution barred ex-confederates from voting but did give the franchise to newly freed African-Americans.

As a result, most people eligible to vote in the next several elections were African-Americans, northern military officers who had stayed in South Carolina after the war, and whites who worked for the Freedmen's Bureau, all of whom overwhelmingly supported the Republican Party.