They include the Saturday Night Diva creation that Diana wore when she memorably danced with John Travolta at a White House ball in 1985.
The Victor Edelstein midnight-blue silk velvet outfit became the most famous dress ever worn by Diana and is valued at up to £300,000.
Saturday Night Fever: The iconic Saturday Night
Diva creation that Diana wore when she memorably danced with John
Travolta at a White House ball in 1985 is on auction
There are five other glamorous Catherine Walker evening gowns up for grabs; another by Victor Edelstein; a Bruce Oldfield black velvet gown; and a Zandra Rhodes white chiffon cocktail dress.
Kerry Taylor Auctions, which is staging the sale in Bermondsey, south-east London on March 19, has hailed the collection of dresses as 'fabulous and historic'.
The Princess wore the Mughal-inspired Catherine Walker pink silk gown by Lord Snowdon in 1997
First Lady Nancy Reagan quietly took Grease heartthrob Travolta aside and whispered that Diana wanted to dance with him.
He later recalled how he crossed the dance floor at midnight and approached her.
He said: 'She turned around and she did that look that she did so, so beautifully and I asked if she would care to dance and she said she'd love to and we danced for twenty minutes to a medley of Grease and Saturday Night Fever.
'I was on cloud nine. She has great rhythm. We did spins and turns. We did a kind of modern fox-trot and she followed me very well.
'"Maybe some day we'll get to do this in a less-watched situation", I said near the end. "That would be great", she replied.'
He described the experience as being like a fairytale'.
A Catherine Walker gown that the late Princess wore in 1991 will also be going on auction at Kerry Taylor auction house
It must have been of special significance to the Princess because in 1997 she chose to wear it for her last portrait by Lord Snowdon - and with the same necklace she had worn twelve years earlier when she had danced at the White House.
The Princess was also photographed wearing the Mughal-inspired Catherine Walker pink silk gown by Lord Snowdon in 1997.
Richly embroidered with layered pink sequins and amber, green and pink crystal beads, it is one of the most lavish of all her gowns.
A Catherine Walker black velvet and beaded evening gown, worn for the Vanity Fair photo-shoot by Mario Testino at Kensington Palace in 1997, is valued at £70,000.
Another Catherine Walker burgundy outfit, worn to the premiere of 'Steel Magnolias' in aid of the Prince's Trust in 1990 and for the State visit to Korea in 1992, is tipped to fetch £60,000.
This Catherine Walker burgundy outfit, worn to
the premiere of 'Steel Magnolias' in aid of the Prince's Trust in 1990
and for the State visit to Korea in 1992, is tipped to fetch £60,000
This Bruce Oldfield black velvet evening gown
has an estimate of up to £50,000, she wore it to the gala opening of Les
Miserables
And the Zandra Rhodes white chiffon cocktail dress, worn to a benefit event at the London Palladium in 1987 is valued at £40,000.
Shortly before her death in a Paris car crash, Diana raised almost £2million for her favourite charities by selling 79 couture creations at an auction at Christie's in New York.
In the catalogue notes to the 1997 sale, Diana wrote: 'The inspiration for this wonderful sale comes from just one person; our son William.'
The young prince, then just 15, had told his mother to sell off her crowded wardrobe for charity.
The Zandra Rhodes white chiffon cocktail dress, worn to a benefit event at the London Palladium in 1987 is valued at £40,000
She set up The People's Princess Charitable Foundation in 1998 with the declared purpose of preserving and displaying Diana's dresses.
She loaned some of the dresses for an exhibition at Kensington Palace for a while.
But on their return to the US they ended up in less grand locations including Disneyworld in Florida, the Pittsburgh Home and Garden Show and the Flying Monkey Movie House at Mill Falls, New Hampshire.
In 2011, Diana's 'exquisite' Emanuel spare wedding dress and shoes fetched £84,000 at a Kerry Taylor Auctions sale in London.
Florida-based socialite Maureen Dunkel snapped up 13 of the dresses at the time for £500,000 but went bankrupt
A Catherine Walker sea-green sequined evening
gown that Princess Diana wore for a State visit to Austria in 1989 that
is tipped to fetch up to £50,000 at auction
A Catherine Walker burgundy crushed velvet
evening gown that Princess Diana wore for a State visit to Australia and
to the film premiere of 'Back to the Future' in 1985 that is tipped to
fetch £50,000 at auction