Sir William Cromer or Crowmer (1416 – July 4, 1450) was the High Sheriff of Kent in 1444.

However, it is known that he was born in Tunstall sometime in 1416 to his father Sir William Cromer and Lady Margaret Squery when she was only 17.

He married a woman named Elizabeth Fiennes by 1435 in Herstmonceux, East Sussex.

When Jack Cade's Rebellion broke out in 1450 both William and his father-in-law James Fiennes were executed in or near the Tower of London before having their head's placed on pikes and carried through the streets.

[2] After William's death, that same year it is said that Elizabeth married Alexander Iden.