M&S executive director, Multi-Channel, Laura Wade-Gery is leaving the retail giant following her maternity leave.
Laura will step down from the Board with immediate effect.
Robert Swannell, chairman of Marks and Spencer Group plc, said: "On behalf of the Board, I would like to thank Laura for the significant contribution she has made in her five years at M&S.  Laura has been a valued member of the Board and instrumental in the improvement and modernisation of our ecommerce and multi-channel capabilities. We wish her all the very best for the future."
Steve Rowe, chief executive, said: "Laura has been a great colleague and has achieved much in her role heading our multi-channel business.  I am grateful to Laura for her contribution and she leaves M&S with my personal thanks and best wishes."
Laura Wade-Gery said: "I have had five very happy years at M&S. I've been away from the business for a year now, and that time has seen some significant changes in both my personal life and in the business. I concluded that the time was right to move on from M&S. I wish Steve and all my colleagues and friends every success".