The site will initially give access to four million pages from 200 newspapers from the 18th and 19th Centuries.
The project is a collaboration between the British Library and Dundee-based IT firm Brightsolid.
Brightsolid's chief executive, Chris van der Kuyl, said: "This new website will help safeguard the future of the world's greatest newspaper collection, a treasure trove of personal stories."
A total of 120,000 pages will be added to daily and 40 million pages will be digitised over the next 10 years, spanning three centuries.
The archive includes articles reporting on the Great Exhibition of 1851 plus stories on infamous murder trials and men, women and children being transported to the other side of the world for minor crimes.
Patrick Fleming, head of reader and reference services at the British Library, said: "We're delighted to be working with Brightsolid to unlock millions of pages of historic newspaper content.
"By making these newspapers available online we open up the archive to people across the UK and around the world, many of whom would never have set foot in our physical reading rooms - but who can now search via their own desktop, accessing thousands of results at the click of a mouse."
The venture is looking to collaborate with publishers of newspapers and the first deal has been signed with Northcliffe, the company behind the Daily Mail and a big chain of local titles.
David Roddick, Northcliffe's commercial director said: "As a nation we are consuming more of our news online than ever before, so it's a natural step forward for the publishing industry to be able to give online access to historic newspapers."
The vast digital storage required for the ever-growing online archive, currently more than 500 terabyte, is being delivered from Brightsolid's state-of-the-art data centres in Scotland.