William Watson (1837–1879), was a surgeon in the 105th Regiment of Pennsylvania Volunteers during the American Civil War. During his duty in the Army of the Potomac, he took part in several battles including Fredericksburg, Chancellorsville, the Wilderness, and Gettysburg notably. Major Watson is recognized most by his contribution to the understanding of soldier life during the Civil War, ranging from the battles themselves to the internal conflicts within the unit.