William I (1020 – 12 November 1087), called the Great (le Grand or Tête Hardie, "the Stubborn"), is Count of Burgundy from 1057 to 1087 and Mâcon from 1078 to 1087. He is a son of Reginald I, Count of Burgundy and Alice of Normandy, daughter of Richard II, Duke of Normandy. William is the father of several notable children, including Pope Callixtus II.