The is a relaunch of the US site and will be available in eight European countries by spring 2011.
The site sells McCartney’s collections, including ready-to-wear, accessories, and lingerie. It also features "Stella's Picks", where the designer recommends her favourite items.
In addition to the site, a Stella McCartney iPad app will be available within the next few months.
Users can also use the site to reserve an item and then pick it up in their nearest store. Social networking via Facebook and Twitter is integrated throughout the website, and users can "like" items to tag their favourites within the site.
The Stella McCartney fashion brand launched in 2001 and has eight stores around the world.
Last July, Adidas, the official sportswear partner of the London 2012 Olympic and Paralympic Games, for its Adidas Team GB ranges.