Sir John Denham (1614 or 1615 – 19 March 1669) was an English poet and courtier. He served as Surveyor of the King's Works and is buried in Westminster Abbey.
Denham was born in Dublin to Sir John Denham, Chief Baron of the Irish Exchequer, and his second wife Eleanor Moore, daughter of the 1st Viscount Moore. He was educated at Trinity College, Oxford and at Lincoln's Inn in London.
In his earlier years Denham suffered for his Royalism; during the English Civil War, he was appointed High Sheriff of Surrey (for 1642) and governor of Farnham Castle.
Denham became a Member of Parliament for Old Sarum in 1661, became a Fellow of the Royal Society on 20 May 1663, and became a Knight of the Bath. He built or commissioned the original Burlington House in Piccadilly in about 1665.
After the Restoration Denham became Surveyor of the King's Works, probably for reasons of his earlier political services rather than for any aptitude as an architect. John Webb, who, as Inigo Jones's deputy had the competence to have served in the post, and complained "though Mr. Denham may, as most gentry, have some knowledge of the theory of architecture, he can have none of the practice and must employ another." There is no evidence that he personally designed any buildings, although he seems to have been a competent administrator; he may however have played some part in the design of his own home, Burlington House. John Webb was appointed Denham's deputy by 1664 and did Denham's work at Greenwich (from 1666) and elsewhere.
Denham made an unhappy marriage, and his last years were clouded by dementia. With Denham's increasing mental incapacity, Charles II requested in March 1669 that Christopher Wren be appointed Denham's "sole deputy"; Wren succeeded him as King's Surveyor upon his death two weeks later. Denham was buried in Poets' Corner of Westminster Abbey.