Stephen Fox was the son of William Fox, of Farley, in Wiltshire, a yeoman farmer.
Stephen was a Chorister of Salisbury Cathedral (c.1634 – c.1640) (Noted in John Evelyn’s Diary as ‘…a poore boy from the quire of Salisbury’ ).
At the age of fifteen he first obtained a post in the household of Algernon Percy, 10th Earl of Northumberland; then he entered the service of Lord Percy, the earl's brother, and was present with the royalist army at the Battle of Worcester as Lord Percy's deputy at the ordnance board. Accompanying 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; he was appointed to the lucrative offices of first Clerk of the Green Cloth and Paymaster of the Forces.
In November 1661, he became member of parliament for Salisbury. In 1665 he was knighted; was returned as MP 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 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 James II, on condition of turning Roman Catholic, but refused, in spite of which he was allowed to retain his commissionerships. In 1685 he was again M.P. for Salisbury, and opposed the bill for a standing army supported by the king. During the Revolution, he maintained an attitude of decent reserve, but on James's flight, submitted to 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-rater, 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.
Stephen Fox was married twice.
Firstly on 8 December 1651 to Elizabeth Whittle (died 11 August 1696), daughter of William Whittle and wife, with issue seven sons, all of whom predeceased him, and three daughters including:Elizabeth Fox (circa 1655 – Tunbridge Wells, 28 February 1681), married in Westminster Abbey on 27 December 1673 to Charles Cornwallis, 3rd Baron Cornwallis (1655 – 29 April 1698). They were the great-grandparents of General Lord Cornwallis.
Jane Fox (died 10 June 1721), wife of George Compton, 4th Earl of Northampton.
Secondly on 11 July 1703 to Christiana Hope (died 17 February 1718), daughter of Rev. Francis Hope and wife Christian Palfreyman, with issue two sons and two daughters, including:Stephen Fox-Strangways, 1st Earl of Ilchester (1704–1776), created Lord Ilchester and Stavordale in 1747 and Earl of Ilchester in 1756; in 1758 he took the additional name of Strangways and his descendants, the family of Fox-Strangways, still hold the Earldom of Ilchester.
Henry Fox, 1st Baron Holland, who followed his father into politics.