Robert Kime, who died in August 2022, was hired by then Prince Charles to redecorate Clarence House and Highgrove in the early 2000s.
Dreweatts auction house will sell the personal collection of Mr Kime from his homes in London and Provence, with one of Lady Sarah's oil paintings included amongst the 750 lots.
The work titled 'Interior, Scotland' was painted in 2010 and carries an estimate of £200 to £400, as part of Lot 684.
Lady Sarah, 59, is the late Queen's only niece and is the daughter of the late Princess Margaret and photographer Antony Armstrong-Jones.
After attending Bedales School, she studied at the Camberwell School of Art and at the Royal Academy Schools.
Lady Sarah has been exhibiting her paintings at the Redfern Gallery since 1995, and her work has appeared in many other exhibitions.
She married British artist and former actor, David Chatto, at St Stephen's, Walbrook, in the City of London on 14 July 1994, with the late Queen Elizabeth II and the late Diana, Princess of Wales among the guests.
The couple share two sons – Samuel and Arthur, born in 1996 and 1999 respectively.
Sam has followed in his family's artistic footsteps and makes his own ceramics, while Arthur joined the Royal Marines last year.
Lady Sarah and her sons joined King Charles and Queen Camilla at a private church service at Crathie Kirk in Scotland earlier this month to mark the one-year anniversary of the late Queen's passing.
Cousins Lady Sarah and Charles have remained close since childhood, with the artist attending major royal events, including the coronation, the annual Easter Sunday service in Windsor and Royal Ascot.
Dreweatts' three-day auction Robert Kime: The Personal collection will take place from 4 to 6 October.
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