Sir William Bucknall (25 July 1633 – 1676), of Oxhey, Hertfordshire, was an English merchant, excise farmer and politician who sat in the House of Commons from 1670 to 1676.
In 1752, he became a Freeman of the Salters’ Company and acquired interests in water supply and shipping.
He was the main businessman in a syndicate formed to farm the customs by Sir Robert Howard and Charles Powlett, Lord St John.
He was joint farmer of excise for London, Middlesex and Surrey from 1665 to 1675.
In 1673 he became JP for St Albans liberty, and was Commissioner for assessment for Hertfordshire, Lancashire, Middlesex and London from 1673 to 1674.