Bloomberg
TalkTalk CEO Dido Harding.
The news, announced on the company's website on Wednesday, comes after the major TalkTalk hack in 2015, which cost the company £42 million.
Harding will be replaced by TalkTalk's current managing director, Tristia Harrison, while Carphone Warehouse cofounder Sir Charles Dunstone will become TalkTalk's executive chairman.
"After seven extraordinary and fulfilling years, during which we have transformed TalkTalk's customer experience and laid the foundations for long term growth, I've decided it's time for me to start handing over the reins at TalkTalk and focus more on my activities in public service," Harding said in a statement.