Sir Thomas Tresham (1534[] - 11 September 1605) was a Catholic recusant politician at the end of the Tudor dynasty and the start of the Stuart dynasty in England.

Rushton Triangular Lodge
Inheriting large estates at the age of 15 from his grandfather, Thomas Tresham I, he had a privileged start to adult life. He was widely regarded as a clever and well educated man, moving in the highest social circles. He was acquainted with William Cecil, the Secretary of State to Queen Elizabeth, and Sir Christopher Hatton, the Lord Chancellor.
Thomas Tresham served as High Sheriff of Northamptonshire for 1573 and was knighted at the Queen's Royal Progress at Kenilworth in 1575.[] Sir Thomas enjoyed a lavish lifestyle, and frequently entertained large numbers of friends and acquaintances. His Catholic religion burdened him frequently with debt and fines. At a time when Queen Elizabeth was anxious about the Catholic threat posed by Spain and by her cousin Mary, Queen of Scots, nonconformists were targets for persecution. Between 1581 and 1605, Tresham paid penalties totalling just under £8,000. (£1,240,000 as of 2012),[]. These heavy financial demands created spiralling debts, with borrowing as his only resource. Tresham's credit never fully recovered. For a landowner who sought personally to direct all matters of estate management, his effective status as a hostage, seized by the government whenever Catholic nations sought to menace the kingdom, was a severe imposition.
He left three notable buildings in Northamptonshire, the extraordinary Rushton Triangular Lodge and the unfinished Lyveden New Bield, both of which have designs based on complicated religious symbolism as well being practical buildings. The triangular shape of the lodge and the profusion of other aspects of the building using the number three both refer to the Christian Trinity and play on the name Tresham.[] It is presumed that Tresham was himself largely responsible for these elements of the designs. He also started in 1577 the market house in Rothwell, which was not completed for some three centuries. Sir Thomas was a considerable landowner at his death in 1605, but his estate had £11,000 of debt(£1,700,000 as of 2012),[].
Marriage and children
In 1566, he married Muriel, a daughter of Sir Robert Throckmorton and Elizabeth Hussey. The Throckmorton family was a wealthy Catholic family from Coughton Court in Warwickshire.
Thomas and Muriel had eleven children, including;
• Sir Francis (d. December 1605)
• Mary (d. 13 October 1664); married the 1st Earl of Cardigan
• Elizabeth; married the 4th Baron Monteagle.
• Frances; married the 10th Baron Stourton.
His elder son, Francis, inherited the titles, estate, and debt, and became embroiled in the Gunpowder Plot later that year along with his cousins Robert Catesby and Thomas Wintour. Imprisoned for his actions, Francis met an early death in December, 1605.