Hugh d'Avranches, 1st Earl of Chester (died July 27, 1101) was one of the great magnates of early Norman England.

Hugh was the son of Richard Goz, viscount of Avranches, in the far southwest of Normandy, and inherited from his father a large estate not just in the Avranchin but scattered throughout western Normandy.

Hugh became an important councilor of William, Duke of Normandy. He contributed 60 ships to the invasion of England, but did not fight at Hastings, instead being one of those trusted to stay behind and govern Normandy.

After William became king of England, Hugh was given large grants of land, and then, in 1071, was made Earl of Chester, with palatine powers in view of Cheshire's situation on the Welsh border.

Hugh spent much of his time fighting savagely with his neighbors in Wales, in the end subduing a good part of northern Wales and the island of Anglesey.

In time Hugh became so fat he could hardly walk; he is often referred to as Hugh the Fat.

He married Ermentrude of Claremont, by whom he had one son, Richard, who succeeded him. Richard married Matilda of Blois, daughter of Stephen, Count of Blois and Adela, a daughter of William the Conqueror. Both Richard and Matilda died in the White Ship disaster (1120), and he was succeeded by his first cousin Ranulph le Meschin, Earl of Chester.