Deller joins Barclays from running her own business, Policy Profile, which has provided PA and CSR advice to clients including Coors Brewers and Coca-Cola Enterprises.
She spent eight years at Diageo, latterly as the drinks group's government affairs director. Prior to that she worked in the public affairs department of Whitbread.
Barclays retains Weber Shandwick for public affairs in the UK and APCO on EU issues. Deller, who reports to group public policy director Mike Davis, said she would be 'assessing all our support requirements against the public policy department issues in the UK'.
She added that there were 'no immediate plans for major changes'.
The banking sector has come under fire in recent years over cash machine charges and irresponsible mortgage lending, which has been condemned by consumer groups for contributing to consumer debt.
Former Barclays CEO Matt Barrett committed a famous PR gaffe when giving evidence to a Treasury select committee two years ago. He confessed that astute customers would steer clear of Barclaycard because of its high interest rates and that he had advised his children to avoid credit cards.
Former Allied Domecq corporate affairs director Stephen Whitehead starts as Barclays director of corporate and external affairs later this month. He replaces Leigh Bruce, who quit after seven years for a career break.