Sir John Gresham (1495 – 23 October 1556) was an English merchant, courtier and financier who worked for King Henry VIII of England, Cardinal Wolsey and Thomas Cromwell.

[2] Gresham invested his money in land, buying the manors of Titsey, Tatsfield, Westerham, and Lingfield, on the borders of Surrey and Kent, as well as estates in Norfolk and Buckinghamshire.

[2] He was a member of the Royal household between 1527 and 1550, first as a gentleman pensioner and later as one of the esquires of the body of King Henry VIII.

[2] In 1539, the king granted Gresham the manor of Sanderstead in Surrey, following the dissolution of the monasteries: it had previously belonged to the Minster of Winchester since the year 962.

[citation needed] In 1541, Gresham was one of the jurors who tried Thomas Culpepper and Francis Dereham for treason - that is, intimacy with Queen Catherine Howard.

[2] In 1547, Sir John Gresham became Lord Mayor of London,[2] and after the end of his year in office he continued to serve as an alderman.

[6] Gresham married firstly, in 1521, Mary Ipswell, with whom he had twelve children between 1522 and 1538: Gresham married secondly, on 15 July 1553, Katherine Sampson (d.1578), widow of Edward Dormer (d.1539), brother of Sir Michael Dormer, Lord Mayor of London in 1541.

The 17th century Greshams sat as Members of Parliament, loyally supported King Charles I throughout the Civil War, and suffered from the victory of Cromwell.

However, his daughter and heiress Katherine Maria Gresham had married William Leveson-Gower, a first cousin of the Marquess of Stafford, later the first Duke of Sutherland, and through Katherine Maria the Titsey estate continued to be owned by Sir John Gresham's descendants until the death of Thomas Leveson Gower in 1992.

By his will, Leveson Gower set up the Titsey Foundation, a charitable trust with the aim of preserving the estate for the benefit of the nation.

Gresham's original Royal Exchange building (destroyed in the Great Fire of London of 1666) was profusely decorated with grasshoppers.