The newly redesigned FIFAWorldCup.com site will include real-time coverage of Friday's draw in Germany, when fans find out who their favourite team will play next summer in the group stages.
The site will be made available in seven world languages and will include archived footage as well as live updates on all 64 matches of the tournament, which kicks off on 9 June 2006.
Emirates Airlines will sponsor the site's interactive section, enabling visitors to comment on the draw in real time.
Yahoo! and Fifa have worked together since 2001, jointly marketing the official World Cup website, which registered more than two billion page views during the 2002 tournament in Korea.
Director of marketing and TV at Fifa, Jérôme Valcke, said: "This web site brings together the best of the FIFA World Cup with the internet expertise of Yahoo!, so that fans from every corner of the world can experience the planet's most popular sporting event."