While the eight-year-old magazine has a tablet edition and a fashion app, it has not previously had an accompanying website.
Reveal.co.uk has been built by the development team behind Hearst's Digital Spy entertainment news website and is edited by former Digital Spy US news editor Lara Martin.
Hearst promised the site would deliver key celebrity news, as well as editorial contributions from the Reveal magazine team.
It has launched with an exclusive interview with Jodie Marsh and 'TOWIE' star Kirk Norcross.
Advertisers on the site include DFDS Seaways, Payday Loans and Nissan.
Reveal magazine's latest audited circulation is 278,642 copies, according to ABC figures for July–December 2011.
This is 14.2% down year on year, against the background of a celebrity magazine sector beset by dwindling circulations.
Jane Ennis, editor of Reveal, said: "I am delighted to unveil the new reveal.co.uk and to also welcome Lara Martin as editor of the new site.
"Her experience as a digital editor in the celebrity world at both MSN and Digital Spy will be of huge value to Reveal overall as we develop the brand across print, digital and social media."Follow @DanFareyJones