Called the ‘Legacy Collection’, it includes a whole range of personal items relating to the Worcestershire-born driver's racing career.
Previously housed in Mansell’s own museum in Jersey, 330 lots are now being sold off as part of an online auction.
The array of memorabilia is vast, including 32 racing helmets from his career, 78 baseball caps, 50 race suits and more than 200 trophies and awards that Mansell picked up throughout his career.
Many of the helmets are estimated to sell for between £10,000 and £15,000, but his "final F1 win helmet" could fetch up to an estimated £50,000, while those from his 1992 championship-winning year are expected to fetch top money too.
More unusual items retained by Mansell include opened and unopened magnums of champagne presented at his racing wins, as well as a commemorative Japanese crystal dagger.
Mansell’s personal number plate ‘5 NM’ is estimated at between £30,000 and £60,000 too, while a bespoke 2020 BMW R18 ‘II Leone Edition’ motorbike could make between £20,000 and £40,000.
Speaking about the auction, Mansell said: “The collection is hugely personal to me. It represents the entirety of my career and is the vast majority of the items of clothing I have worn during my racing career; the helmets, suits and all the trophies I have won during more than 30 years of topflight motorsport.
“It is, in short, the material manifestation of the most significant moments of my career and it represents everything that I worked for from my teenage years through to the end of my racing career."
Mansell closed his museum in St Helier in 2019 to clear space for an expanding car sales operation with Mitsubishi and Hyundai.
However, earlier this year, Mansell, along with his son Leo, announced they were parting ways with the two franchises and were closing their car sales operation.
Since then, the father-and-son team have created ‘The Ramp’ – a bike sales and servicing outfit.
All items are being sold online by RM Sotheby’s, with the auction running between 4 and 11 October.
Want to find out more about the stories making the headlines? Don't miss Channelcast - the Channel Islands current affairs podcast brought to you by ITV News: