Swannell will join M&S as non-executive director on 4 October, and will take over as chairman when Sir Stuart steps down in January 2011.
M&S says Sir Stuart will continue as chairman until January to “ensure a smooth transition” of leadership.
Swannell is currently chairman of entertainment and retail group HMV Group where he has helped oversee a turnaround in fortunes.
He has spent 30 years in investment banking with Schroders/Citigroup and was formerly vice-chairman Citi Europe and co-chairman of Citi’s European Investment Bank.
He will work alongside Marc Bolland who replaced Sir Stuart as CEO in May.
Sir Stuart Rose, says: “I am delighted that Robert is to be M&S’ next Chairman. His appointment completes our succession plan and enables us to revert to standard governance practice. His considerable experience of both the City and the commercial world will be a real asset to the Board and the business.”
Robert Swannell said: “It is a privilege to be asked to Chair one of the world’s greatest brands. I look forward to joining the M&S team and working with my new colleagues on the Board.”
In its latest results, M&S reported that UK sales were up 4.8% while like for like sales, which strip out sales from new stores, increased 3.6% during the 13 weeks to 3 July.