Dixons Carphone's deputy chairman and senior independent director John Allan has quit the firm to join Tesco.
Roger Taylor will continue as the sole deputy chairman at the parent company for PC World, Currys and Carphone Warehouse.
Allan will become supermarket chain Tesco's new chairman.
Sebastian James, group chief executive at Dixons Carphone, said: "John Allan has been an excellent chairman to Dixons Retail Plc for many years, playing an important part in a great turnaround story.
"He has also been a valuable force for good on the Board of our newly merged company, Dixons Carphone.
"As a result, though we are sorry that he will be leaving us, we are delighted for both him and for Tesco that he has accepted this important post and we wish him every good luck in this new adventure."
This news comes after Sebastian James hinted the company may stock the upcoming Apple Watch this Easter.