Sir William Dunch from his memorial at St Peter's Church, Little Wittenham, Oxfordshire
Sir William Dunch (1578–1611) was an English politician during the reign of King James I.
Dunch represented Wallingford in Berkshire (now Oxfordshire) as an MP in 1603.  That same year he was knighted by King James I. He was the son of Sir Edmund Dunch (1551–1623). He graduated from Balliol College, Oxford in 1595. He married Mary Cromwell in 1599, the daughter of Sir Henry Cromwell and aunt to Oliver Cromwell. It is believed that the variant name for the rounded hills Wittenham Clumps (Mother Dunch's Buttocks) near the Dunch's family seat at Little Wittenham is associated with her. William’s brother Samuel Dunch (1593–1666) represented Wallingford in 1620, as did William’s son Edmund (1602–1678).