Viscount Daventry, of Daventry in the County of Northampton, is a title in the Peerage of the United Kingdom. It was created on 6 May 1943 for Muriel FitzRoy (née Douglas-Pennant), in honour of her late husband, the Hon. Edward FitzRoy, Speaker of the House of Commons from 1928 until his death in 1943. The first Viscountess was the sister of Frank Douglas-Pennant, 5th Baron Penrhyn, whilst Edward FitzRoy was the second son of Charles FitzRoy, 3rd Baron Southampton, and a male-line descendant of Charles FitzRoy, 2nd Duke of Grafton. Lady Daventry was succeeded by her eldest son, the second Viscount. He was a Captain in the Royal Navy. He was succeeded by his nephew, the third Viscount. He assumed the additional surname of Newdegate, which was that of his father-in-law. As of 2012[update] the title is held by his son, the fourth Viscount, who succeeded in 2000. As a male-line descendant of both the third Baron Southampton and the second Duke of Grafton he is also in remainder to these peerages.
The heir apparent is the present holder's son Hon. Humphrey John FitzRoy Newdegate (b. 1995)