Thomas Wancklyn (died 1694), of Heywood House, Westbury, was an English and politician who sat in the House of Commons during the late 17th century. He represented Westbury as a Member of Parliament and was active in local Wiltshire affairs.^[1]

Wancklyn may have married three times. On 7 August 1647, he married Mary (née Capell) Ley, the widow of Henry Ley, 2nd Earl of Marlborough and daughter of Arthur Capell, 1st Baron Capell of Hadham. Mary died 2 June 1670. The following year, Wancklyn married Frances Brandsby, also a widow, on 9 July 1671. He may have also married a third woman named Mary.^[1]

Wancklyn died in 1694.^[1]