One of only two built, the 55-year-old car has been described as "one of the prettiest ever Ferraris" with a "design without fault".
The Spyder was originally fitted with a 2.5-litre engine but had a full restoration in 1982 and now has a 3-litre V12 engine which develops 320bhp.
Two other models - a 1966 Ferrari 206 S Dino Spyder and 1952 Ferrari 225 Sport Spyder Tuboscocca - sold for $4.1 million each.
Peter Haynes, from RM Auctions, said: "The 1957 Ferrari really ticked all the boxes and because it has been in single ownership for the last 30 years no one has had the chance to buy it. It also is a matching numbers car and that adds to its desirability.