Sir Stephen Fox (27 March 1627 – 28 October 1716) of Farley in Wiltshire, of Redlynch Park in Somerset, of Chiswick, Middlesex and of Whitehall, was a royal administrator and courtier to King Charles II, and a politician, who rose from humble origins to become the "richest commoner in the three kingdoms". He made the foundation of his wealth from his tenure of the newly created office of Paymaster-General of His Majesty's Forces, which he held twice, in 1661–1676 and 1679–1680. He was the principal force of inspiration behind the founding of the Royal Hospital Chelsea, to which he contributed £13,000.
 Stephen Fox was a younger son of William Fox, of Farley, Wiltshire, a yeoman farmer, by his wife Margaret Pavy, a daughter of Thomas Pavy of Plaitford, Hampshire. His eldest surviving brother was John Fox (1611–1691), Clerk of the Acatry to King Charles II. Stephen's sister was Jane Fox (1639–1710), who married Nicholas Johnson (died 1682), who was Paymaster-General of His Majesty's Forces from 1680 to 1682, following Stephen Fox's second shorter term in that office.
 Stephen was a Chorister of Salisbury Cathedral in Wiltshire (c. 1634 – c. 1640) and was mentioned in John Evelyn's Diary as a poore boy from the quire of Salisbury. His elder brother John Fox had obtained a position in the royal court on the recommendation of the Dean of Salisbury Cathedral, and first introduced his younger brother Stephen to the royal court, specifically to the household of the royal children, as "supernumerary servant and play-fellow". At the age of fifteen Stephen obtained a post in the household of Algernon Percy, 10th Earl of Northumberland; then he entered the service of Lord Percy, the earl's younger brother, and was present with the royalist army at the Battle of Worcester as Lord Percy's deputy at the ordnance board. Accompanying King Charles II in his flight to the continent, he was appointed manager of the royal household on the recommendation of Edward Hyde, 1st Earl of Clarendon.  Clarendon described him as "a young man bred under the severe discipline of Lord Percy ... very well qualified with languages, and all other parts of clerkship, honesty and discretion".
 The skill with which Fox managed the finances of the exiled court earned him further confidence and promotion. He was employed on several important missions, and acted eventually as intermediary between the king and General Monck. Honours and emolument were his reward after the Restoration of the monarchy; he was appointed to the lucrative offices of First Clerk of the Green Cloth and Paymaster of the Forces.
 Immediately on his Restoration, King Charles II struggled to fund the new standing army, a concept invented by Oliver Cromwell during the Civil War and the following Commonwealth. The problem was solved by Fox, who was deemed "one of the financial wizards of his age", and from 1654 to 1660 had managed the finances of the exiled king with great success.
 The king established a new office of Paymaster of the Forces, of which Fox was the first occupant, with premises in a wing of Horseguards in Whitehall. His success in restoring the financial position of the army stemmed from his ability to raise credit in the City of London, largely thanks to his reputation for honesty and reliability, which would later be repaid to him by the Treasury, when Parliament so voted. The yield from bills passed to this effect were often below that forecast, which in the absence of loans would leave the troops unpaid. Fox, however, was personally liable for the loans he raised, and to compensate him for the great risks he undertook, he was allowed to retain certain profits on his repayment by the Treasury. He charged the Treasury 6% on the funds he had borrowed, but much of that he repaid to his own creditors.
 He was allowed other perquisites, including 2% bonus on capital and interest repaid to him by the Treasury, and "poundage" from 1667 which allowed him to retain 4 pence, and from 1668 one shilling, in every pound of army pay, ostensibly to cover administration costs, but in reality mostly profit. This therefore amounted to one twentieth of all army pay, an annual income for Fox of about £7,000, added to his official salary of £400 per annum, and whatever he could save from borrowing at rates below 6%. In just 20 months from January 1665 to September 1666 he advanced a total of £221,000 for army pay, on repayment of which he received interest from the Treasury of almost £13,000. In addition he received a further 2% bonus, worth another £3,000 and also poundage.  This office he held for 15 years between 1661 and 1676, and for another year in 1679–1680.
 In November 1661 he became a Member of Parliament for Salisbury. In 1665 he was knighted; was returned as a Member of Parliament for Westminster on 27 February 1679, and succeeded the Earl of Rochester as a Commissioner of the Treasury, filling that office for twenty-three years and during three reigns. In 1672 he bought the manor of Redlynch in Somerset, where he built a new house in 1708–1709.
 In 1680 he resigned the paymastership and was made First Commissioner of Horse. In 1684 he became sole Commissioner of Horse. He was offered a peerage by King James II, on condition of converting to Roman Catholicism, but refused, in spite of which he was allowed to retain his commissionerships. In 1685 he was again an MP for Salisbury, and opposed the bill for a standing army supported by the king. During the Glorious Revolution, he maintained an attitude of decent reserve, but on James's flight, he submitted to the new King William III, who confirmed him in his offices. He was again elected for Westminster in 1691 and 1695, for Cricklade in 1698, and finally in 1713 once more for Salisbury.
 It is his distinction to have founded Royal Hospital Chelsea, to which he contributed £13,000. As a statesman he was second-rate, but as a public servant he creditably discharged all the duties with which he was entrusted. Unlike some other statesmen of his day, he grew rich in the service of the nation without being suspected of corruption or forfeiting the esteem of his contemporaries.
 Fox married twice:
 Fox had the following residences and estates:
 Of Sir Stephen's garden, this was to be said, that almost all his fine ever-greens were raised in the places where they stood; Sir Stephen taking as much delight to see them rise gradually, and form them into what they were to be, as to buy them of the nursery gardeners, finish' d to his hand; besides that by this method his greens, the finest in England, cost him nothing but the labour of his servants, and about ten years patience; which if they were to have been purchased, would not have cost so little as ten thousand pounds, especially at that time: It was here that King William was so pleased that according to his majesty's usual expression, when he lik'd a place very well, he stood, and looking round him from the head of one of the canals, Well says his majesty, I cou'd dwell here five days; every thing was so exquisitely contrived, finish'd, and well kept, that the king, who was allow'd to be the best judge of such things then living in the world, did not so much as once say, this or that thing cou'd have been better. Fox constructed further buildings including:
 Fox died on 28 October 1716, aged 89, at his house in Chiswick. He was buried in the Church he rebuilt at Farley, where survives his mural monument. He left assets with an estimated value of over £174,000.