Orange will now join Eurostar, Heineken and Visa International as official tournament sponsors when the World Cup starts in September next year.
The mobile phone giant has previously been involved with rugby, having worked with the French Rugby Federation and sponsored the Romanian national team.
Dr Syd Millar, chairman of the IRB, said: "The appointment of a world leader in the mobile communications field further highlights the enormous attraction and prestige of the tournament as a major event on the world sporting calendar."
Last week, Visa International said it was to promote five of the world's greatest rugby players through its Visa Rugby Legends campaign, including former England captain Martin Johnson, ex-All Black Zinzan Brooke, John Eales of Australia, Philippe Sella of France and Joel Stransky of South Africa.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .