A tweed jacket and kilt was the first of 549 lots to go under the hammer, with the late DJ's Highland suits going for £280.
The auction includes gold suits, Cuban cigars and the broadcaster's beloved Rolls-Royce.
The sale will raise money for Sir Jimmy's charitable trust.
His trademark tracksuits and jewellery, including a £12,000 gold and diamond-encrusted Rolex watch, gold identity bracelet and rings, are all on offer along with the first ever chair from his Jim'll Fix It TV show.
Around 300 people packed Savile Hall, at the Royal Armouries with many bidders taking part over the phone and via internet.
Lot one - the Highland suit - was bought by a local man on the front row.
As the auction continued, some items started to soar above their estimates.
A Scottish shepherd's crook estimated to sell for between £30 and £60 went for £380.
A tireless charity worker, Sir Jimmy is thought to have raised more than £40 million for good causes in his lifetime.
He died just before his 85th birthday last year and requested his belongings be sold for charity after his death.