Sir Jeffry Wyattville (3 August 1766 – 18 February 1840) was an English architect and garden designer. His original surname was Wyatt, and his name is sometimes also written as Jeffrey and his surname as Wyatville; he changed his name in 1824.

He was trained by his uncles Samuel Wyatt and James Wyatt, who were both leading architects. He is mainly remembered for making alterations and extensions to Chatsworth House and Windsor Castle. He also completed his uncle James's gothic Ashridge in Hertfordshire.

His largest commission the remodelling of Windsor Castle begun in 1824, when Parliament voted £300,000 for the purpose. The eventual cost was over £1,000,000 (a quarter of which covered furnishing). A competition was held between four invited architects, Wyatville, Robert Smirke, John Nash & John Soane, the architects (with the exception of Soane who withdrew from the competition) submitted their designs, in June Wyatville was announced as the winner. The foundation stone was laid on the 12th August 1824 by King George IV at what would become the George IV gateway. Wyatville took up residence in the Winchester Tower in the castle in 1824 and would use it for the rest of his life. Eventually the Upper Ward of the Castle would be reconstructed.

He was knighted by King George IV in 1828. He was buried in St. George's Chapel, Windsor Castle on the 25th February 1840, his memorial stone is in the north - east corner behind the high altar, and bears this inscription:

In the vault beneath are
deposited the remains of
Sir Jeffry Wyatville R.A.
under whose direction
the new construction and
restoration of the ancient
and royal castle of Windsor
were carried out during the
reigns of George the 4th
William the 4th and of
Her Majesty Queen Victoria
he died February 18th A.D. 1840
in the 74th year of his age

In 2007 a new residential street in Buxton, Derbyshire, was named Wyatville Avenue (with only one t) to commemorate Sir Jeffry Wyattville's impact on the town.