M&S will open a 157,000 sq ft (14,585 sq m) flagship at Westfield London in the northeast corner of the scheme. The£1.6 billion development covers 46 acres (20 ha), with a total of 1.5 million sq ft (139,350 sq m) of retail space.
The unit is located over three floors, with a food hall on the lowest level and fashion and homewares filling the remainder of the store.
The shop will be the biggest of the anchors at Westfield London. House of Fraser, Next, Waitrose and Debenhams are also taking key units. As well as these anchor stores, the centre will be home to 265 shops and a selection of bars and cafés.