The Nikon D800 is a professional grade full-frame digital single-lens reflex camera produced by Nikon. It was officially announced on February 7, 2012 and went on sale in late March 2012 for the suggested retail price of $2999.95 in the U.S., £2399 in the UK, and €2892 in the Eurozone. Shortly after the camera went on sale, Nikon's UK subsidiary increased the price of the D800 in that market by £200 to £2599, saying that the original price was due to an "internal systems error". However, Nikon honored the original price for all pre-orders placed before March 24, and added that no price changes would be made in other markets.

The Nikon D800 achieved a new 'king' result in the DxOMark sensor rating by toppling the Nikon D4 by 4 points, even though the D800 is cheaper, being about half the D4 price (better quality-to-price ratio).

The D800E is a specialized version which uses a new optical anti-aliasing filter with no low pass filter effect (no blurring) to obtain the sharpest images possible. Nikon claims that possible aliasing effects (moiré) can be lessened by software-processing in camera or external programs like Nikon´s Capture NX2. The D800E version will be available in mid April 2012 for a suggested retail price of $3,299.95 in the U.S. and €3171 in the Eurozone. The UK price was initially announced as £2689, but at the same time that Nikon UK announced its price error on the D800, it also increased the price of the D800E to £2899. All pre-orders made prior to March 24 will still be filled at the originally announced price.