William Herbert, 2nd Earl of Pembroke (5 March 1451 – 16 July 1491) was an English nobleman and politician. He was the son of William Herbert, 1st Earl of Pembroke and Anne Devereux. His paternal grandparents were William ap Thomas and Gwladys, daughter of Dafydd Gam, and his maternal grandparents were Walter Devereux, Lord Chancellor of Ireland and Elizabeth Merbury.
He succeeded his father in the earldom in 1469. In 1479, he was forced by Edward IV to surrender the earldom with its accompanying lands in Wales, and was created Earl of Huntingdon. William had hoped to restore to his family the Earldom of Pembroke. Awarding lands in the south-west of England meant that Edward had moved the family influence out of Wales. A Yorkist, he married Mary Woodville, sister of the queen, Elizabeth Woodville, and they had one daughter, Elizabeth Herbert, 3rd Baroness Herbert.
Herbert remained loyal to Richard III. After the rebellion of 1483 he received the post of Chief Justice of South Wales, which had been the Duke of Buckingham's.
After his marriage to his second wife, Katherine, an illegitimate daughter of King Richard III of England in 1484, he received an annuity of some £1,000 pounds a year, nearly doubling his income. Katherine is presumed to have died by 1487, because when William participated in the coronation of his first wife's niece, Elizabeth of York, he was noted to have been a widower.