Thomas Williams (13 May 1737 – 30 November 1802) was a Welsh industrialist and politician who was a member of Parliament for Great Marlow and High Sheriff of Anglesey.

Williams, known to his Welsh speaking workmen as Twm Chwarae Teg ("Tom Fairplay"), once complained to the magistrate at Llanidan that the villagers on Anglesey raided his fields and stole the turnips intended for his cattle and used them to feed their families.

Williams' tenacity as a lawyer was very evident when acting for the Hughes family of Llysdulas who were in an acrimonious dispute with Sir Nicholas Bayly of Plas Newydd concerning the Parys Mountain copper mine.

Williams emerged from the dispute as the managing partner with the Revd Edward Hughes and John Dawes in the Parys Mine Company.

He built himself a fine mansion there called Temple House and used the mills for smelting copper brought from his Welsh mines.

Likewise the Mona mine (adjoining Parys) output was smelted by the Stanley Company in both Lancashire and South Wales.

Other Companies dealt with manufacture at Greenfield near Flint and in the Thames Valley, Chemical Works (vitriol) at Garston Liverpool and still others with warehousing and banking.

Williams claimed to have invested £70,000 in this trade and petitioned parliament in 1788 when a bill was being discussed to prevent British ships from carrying slaves.