The move follows a pre-season US tour earlier this year and the announcement of a partnership with Disney's 'Wide World of Sport'.
It also marks the first time a European club has created a dedicated membership site for its fans in America.
The new site, chelseafc.com/America, offers bespoke content for football fans in North America, including a social networking "members map" facility that will allow supporters to search and communicate with one another.
Fans can upload their own photos, chat online and access the latest news from the club. The club has visited the US four summers in a row and will be returning again in 2009.
The club has secured a number of high-profile columnists to write for the site, including Arash Markazi of Sports Illustrated.com and Jack Bell of The New York Times.
Peter Kenyon, chief executive of Chelsea, said: "Fan engagement is important to Chelsea on all levels and we recognise the cultural differences between UK and US fans so content from grass roots to elite level will be delivered in a way that the American fan will relate to more."
This article was first published on brandrepublic.com