William Ash (died 1411), of Dorchester, Dorset, was an English politician.
He married a woman named Eleanor, who died in 1416.
He was a Member (MP) of the Parliament of England for Dorchester in 1394.[1] He was also bailiff of Dorchester from Michaelmas 1396 to 1397, 1399 to 1400, and 1405 to 1406.[1] Over the years Ash was much involved both as grantor and recipient in conveyances of property in Dorchester.[1]