The sale includes more than 100 lots, from clothing and jewellery to guitars and photographs, many of which were given to Harrison's brother Harry and other relatives by the star himself.
The most coveted piece of the sale is a black leather jacket which was worn by Harrison throughout the band's early years and is expected to fetch up to $192,000 (£120,000).
Stephanie Connell, a representative for auctioneers Bonhams, says, "This leather jacket is instantly recognisable and was an important part of the Beatles image in their early years. George Harrison was one of the pioneers of this signature style... It is extremely exciting to see such an iconic part of Beatles history emerge onto the market."
Other items for sale include a pair of Harrison's custom-made leather boots, which have an estimated price of $24,000 (£15,000), an orange shirt he wore at a charity concert in 1971, and a guitar used by Sir Paul MCCartney during the 1950s as a member of pre-Beatles group The Quarrymen.
An archive of more than 1,000 Beatles photographs is also for sale and is expected to make around $80,000 (£50,000).
The Bonhams auction will take place in London on 12 December (12).