Harding is the daughter of Lord Harding, and the grand-daughter of Field Marshal John Harding, 1st Baron Harding of Petherton, who commanded the Desert Rats in World War II. Raised on the family pig farm in Dorset, she was educated at St Antony's Leweston from 1978–85. She then graduated from the University of Oxford in Philosophy, Politics and Economics (the blaggers degree), where she studied under Vernon Bogdanor and alongside David Cameron; and then at Harvard Business School, gaining an MBA.
On graduation she joined the management consultancy
McKinsey & Company. Leaving to become marketing director at
Thomas Cook Group, she was then appointed commercial director at
Woolworths Group. She then joined
Tesco within Sir Terry Leahy's office as international support director, before being appointed commercial director of “added-value foods” in 2001.
Resigning her position in October 2007, she joined the board of directors at
Sainsbury's as convenience director. She was named CEO of
TalkTalk in 2010, during the period when the group split its Carphone Warehouse retail operation from the group telecoms operation. She was appointed as a non-executive director on The Court of
The Bank of England in July 2014. She has also served on the boards of
British Land and
Cheltenham Racecourse.
In October 2015,
TalkTalk experienced a "significant and sustained cyber-attack", during which personal and banking details of up to four million customers is thought to have been accessed. City A.M. described her responses as "naive", noting that early on when asked if the affected customer data was encrypted or not, she replied: "
The awful truth is that I don’t know". Her "inflexible line" on termination fees was also criticised. Marketing ran a headline, "T
alkTalk boss Dido Harding's utter ignorance is a lesson to us all". The Evening Standard noted that "It has been a tough week for TalkTalk boss Dido Harding, facing complaints from customers and calls for her head."
In February 2017 Harding announced she would stand down after 7 years as CEO of TalkTalk in May 2017 to focus more on her public service activities. She was appointed chair of
NHS Improvement which is responsible for overseeing
all NHS hospitals, comprising foundation trusts and NHS trusts, as well as independent providers that provide NHS-funded care in October 2017.