Sir John Vanbrugh (1664-26 March 1726) was an English architect and dramatist, probably best known as the designer of Blenheim Palace.

Vanbrugh was born in London but educated in France, where his Protestant family originated. After military service which included a period of imprisonment in the Bastille for spying, he became a successful playwright with The Relapse (1696), a great hit on the London stage. His works were mostly comedies, and he joined William Congreve to manage the Haymarket Theatre in the West End. Vanbrugh became a leading exponent of Restoration comedy.

In 1702, he added the title of architect to his CV with his design for Castle Howard, and this led to his being selected as the architect of Blenheim. Although his plans were unpopular with many (including Sarah Churchill, its future resident), it was eventually completed, and Vanbrugh became Comptroller of Royal Works in 1714. He was knighted in 1724.

His associations with London are commemorated in Greenwich, London where a road (Vanbrugh Hill) and a pub (The Vanbrugh Tavern) to the east of Maze Hill railway station both bear his name (a building at York University also bears his name due to its proximity to Castle Howard).

A palatial building resembling a Scottish castle or fortress (now housing private apartments, but previously a school and an orphanage) overlooks Greenwich Park at 121 Maze Hill (blue plaque). Vanbrugh built this imposing pile while working on the nearby Greenwich Hospital and at Woolwich Arsenal, and lived in it (and a Whitehall town house) from 1719 until his death in 1726. Once known as 'Bastile House', today it is 'Vanbrugh Castle', and is included within the boundaries of the World Heritage Site of Maritime Greenwich.

Vanbrugh also designed buildings on neighbouring plots, including one known as Mince Pie House (also the Nunnery and Sherwood) occupied by his brother Phillip. However, out of several buildings developed on a 12-acre site, only the 'Castle' survives; Mince Pie House was demolished in 1911.