The Deep is a public aquarium situated at Sammy's Point, at the confluence of the River Hull and the Humber estuary in Hull, England. It opened in March 2002.

Billed as 'the world's only submarium', the tanks contain thousands of sea creatures (including seven species of shark), 2,500,000 litres (550,000 imp gal; 660,000 US gal) of water and 87 tonnes (96 tons) of salt housed in a building designed by Sir Terry Farrell and built as part of the UK National Lottery's Millennium Commission project.

The Deep is also a centre for marine research. Staff marine biologists look after the animals in The Deep’s collection as well as carrying out research into the marine environment.

The Deep is a charitable public aquarium dedicated to increasing peoples enjoyment and understanding of the world’s oceans. It is one of the most successful millennium projects in the Country.