John Lewis will spend £20 million to refurbish its store at the Bluewater shopping centre in Kent.
John Lewis will convert the basement floor into new retail space. It will also add a Waitrose foodhall to the store to open next summer.
John Lewis Bluewater managing director Simon Russell said: "We are confident that customers at John Lewis Bluewater will really appreciate the enhanced shopping experience in our anchor shop and the addition of the Food Hall."
Bluewater was ranked number nine in Experian's Retail Ranking, which rates the UK's top retail destinations.
John Lewis has 27 stores in the UK.