John Vardy was born to a simple working family in Durham. His early training is obscure. His career at the Office of Works, which demanded most of his attention throughout his life, began in May 1736, when he was appointed Clerk of the Works at Greenwich Hospital. He was Clerk of the Works at Hampton Court Palace, January 1745 to 1746; Clerk of the Works at Whitehall, Palace of Westminster and St James's Palace, December 1746 to 1754; Kensington Palace, July 1754 to 1761. He also served as Clerk of the Works at Chelsea Hospital and as Surveyor to the Mint.
Vardy and William Kent 
His relations with William Kent, his senior at the Board of Works, began about 1736 and remained close. Vardy prepared for publication the classic of the Palladian revival, Some Designs of Mr. Inigo Jones and Mr. William Kent, 1744. He redrew and engraved Kent's drawing of the Great Hall at Hampton Court, and drew up Kent's ambitious designs for new Houses of Parliament, under Kent's direction. After Kent's death Vardy and Thomas Robinson saw Kent's Horse Guards, Whitehall, through to completion; Vardy published engravings of his redrawings of the plan and elevation.
Private clients 
Vardy's routine at the Office of Works constrained his time to devote to private clients. His london buildings have mostly suffered the fate of city constructions and have gobne. His most prominent surviving work is Spencer House, St. James's, where, ironically the chief fame is garnered by the very early neoclassical interiors of the upper floor, by James "Athenian" Stuart.
For Joseph Damer, 1st Earl of Dorchester Vardy probably designed Dorchester House, Park Lane, London, begun in 1751-52. He exhibited designs for interiors at the Society of Artists, 1764. The house was demolished in 1849.
Vardy's will mentions his brother Thomas Vardy, carver in Park Street, Grosvenor Square, and his son, John Vardy, Jr. who succeeded his father as Surveyor to the Royal Mint. He remodeled and extended Giacomo Leoni's Queensberrry House in Burlington Gardens, for Henry Paget, 1st Earl of Uxbridge, in 1785-89; as Uxbridge House it survives, housing the Royal Bank of Scotland.
Gallery of architectural work 
- Howard Colvin, Biographical Dictionary of British Architects 1600-1840, 3rd ed. (Yale University Press) 1995, s.v. "Vardy, John" observes "If not actually a pupil of Kent in the strict sense, he was certainly one of his most faithful disciples." Michael I. Wilson, William Kent, Architect, Designer, Painter, Gardener, 1685-1748(1984) p. 240 remarks, "This selfless disciple of Kent receives on the whole insufficient credit for the way in which he loyally promoted the best interests of his chief."
- History of the King's Works, vol. 5; Colvin 1995.
- Colvin 1995.
- Colvin 1995, s.v. "Vardy, John Jr."