William de Ros, 2nd Baron de Ros (1255 - 1317) was a claimant to the crown of Scotland. He was the son of Robert de Ros, 1st Baron de Ros.

William 2nd Baron de Ros of Hamlake, Yorkshire, was one of the claimants of the crown of Scotland, in 1292, during the reign of Edward I, and was summoned to Parliament during the reigns of Edward I and Edward II. He succeeded to the family honours and estates on the death of his mother. He was an unsuccessful competitor for the crown of Scotland, founding his claim on his descent from his great grandmother, Isabel, daughter of William I of Scotland. He was buried at Kirkham Priory.

His wife was Maud or Matilda de Vaux (b. 1275), whom he married in 1287.

Through this marriage the patronage of Penteney and Blakeney Priories in Norfolk and of Frestun in Lincolnshire, came into the De Ros family. The De Vaux family was descended from Robert De Vaux who came over from Normandy with William I of England.

Their children were Margaret de Ros and William de Ros, 3rd Baron de Ros.