William FitzEustace de Vesci (c1125–1184) was an Anglo-Norman feudal lord and Sheriff.
He was born in Knaresborough castle, Yorkshire to Eustace Fitz John de Burgo, Lord of Knaresborough and Beatrice de Vesci.
He was appointed Sheriff of Northumberland from 1155 to 1170 and then Sheriff of Lancashire from 1166 to 1170.
In 1174 he joined other knights such as Bernard Balliol and Robert III de Stuteville under the command of Ranulf de Glanville, Sheriff of Westmorland to attack an invading Scottish army then besieging Alnwick castle in Northumberland. The Scottish king William I of Scotland (William the Lion) was captured and the invasion successfully repelled. [1]
He married Burga de Stuteville, the sister of Robert III de Stuteville. They had two sons, Eustace and Warine. Eustace married Margaret Fitz William, illegitimate daughter of William the Lion of Scotland.[1]