Looking at DSLRs only, it is the second highest seller, beaten only by the Canon EOS 550D, a budget entry-level DSLR.
The Nikon D800 was launched back in February, and is the world's highest resolution full-frame camera, featuring 36 million pixels.
Currently, the Amazon listing shows that it is due for release on March 26th.
Retailing for £2,399, it is unusual to see such an expensive camera selling so well on Amazon, which finds most of its camera business through point and shoot cameras and entry level DSLRs.
Amazon's top 20 cameras sales list includes 19 compact cameras and the Canon EOS 550D.
Amazon is not currently offering the more expensive pro Nikon D4, which retails for around £4,800 elsewhere.
Earlier in the month, Nikon told us that pre-orders for the D800 have been 'unprecedented', meanwhile possibly its biggest rival, the Canon 5D Mark III is not currently available for sale on Amazon.
There are no compact system cameras currently in the Amazon UK top 40 best-sellers, however the Panasonic G3 tops the separate list of CSCs.
Sign up for Black Friday email alerts!
Get the hottest deals available in your inbox plus news, reviews, opinion, analysis and more from the TechRadar team.
Amy has been writing about cameras, photography and associated tech since 2009. Amy was once part of the photography testing team for Future Publishing working across TechRadar, Digital Camera, PhotoPlus, N Photo and Photography Week. For her photography, she has won awards and has been exhibited. She often partakes in unusual projects - including one intense year where she used a different camera every single day. Amy is currently the Features Editor at Amateur Photographer magazine, and in her increasingly little spare time works across a number of high-profile publications including Wired, Stuff, Digital Camera World, Expert Reviews, and just a little off-tangent, PetsRadar.