William Perkins Black (November 11, 1842 – January 3, 1916) was a lawyer and veteran of the American Civil War.

He received America's highest military decoration – the Medal of Honor – for his actions at the Battle of Pea Ridge, Arkansas, in 1862.

He was the brother of John C. Black, Commander of the Grand Army of the Republic, who was also a Medal of Honor recipient.

As a lawyer, Black was best known for having served as defense counsel to the people charged with inciting the Haymarket Riot of 1886.

Citation: Single-handedly confronted the enemy, firing a rifle at them and thus checking their advance within 100 yards of the lines.