Sir Michael Duff, 3rd Baronet

Sir Charles Michael Robert Vivian Duff, 3rd Baronet (3 May 1907 – 3 March 1980) was a British socialite who was Lord Lieutenant first of Caernarvonshire, and then of Gwynedd.

He had one sibling, Victoria Maud Veronica Duff (1904–1967, married John Edward Tennant).

Surrounded by the estate's seven-mile-long stone wall, the Duffs lived in Vaynol New Hall, which had been built in 1800.

Sir Michael Duff-Assheton-Smith, as he then was, married first, on 5 March 1935, the Hon Millicent Joan Marjoribanks (born 1906), daughter of the 3rd and last Baron Tweedmouth.

Sir Michael Duff, as he had subsequently become, married as his second wife, on 14 July 1949, Lady (Alexandra Mary Cecilia) Caroline Paget (1913–73), the eldest daughter of Charles Paget, 6th Marquess of Anglesey, and his wife, Lady Marjorie Manners, the eldest daughter of Henry Manners, 8th Duke of Rutland.

Lady Caroline was at the time, according to James Lees-Milne, diary 9th Oct 1949, pregnant, the father being Duff Cooper - her uncle by marriage.

A documentary screened on BBC Two Wales in 2005 (Faenol: Secrets Behind the Wall) featured Charles Duff discussing his childhood, the bisexuality of his adoptive parents, their marriage of convenience, and the details of his parentage.