William Barksdale Tabb (September 11, 1840 – December 4, 1874) was an American lawyer and military officer in the Confederate States Army.

He was the commander of his regiment and is mainly known for being in the Battle of Sayler's Creek in which the Confederate States sustained over 7,000 casualties.

On May 9, 1873, Tabb served as a second in a duel in Richmond, Virginia, involving pistols, during which both principals—John B. Mordecai and W. Page McCarthy—were injured.

[1][3] After Mordecai died, McCarthy was charged with murder, with each of the seconds considered an accessory before the fact.

[4] Tabb and the other seconds spent several days in jail before a judge ruled they could be freed on bail.