Mary Francis, who is currently serving on the board at Swiss Re Group and has previously held non-executive positions at Aviva, Cable & Wireless Communications, the Bank of England and Alliance & Leicester, will join the board of the bank at the start of October.
"I am pleased to announce Mary's appointment to the Barclays' board," said John McFarlane, group chairman of Barclays. "Mary brings extensive board-level experience across a number of different industries and having worked with her in the past I am fully aware of the wisdom and value she brings to the board.
"She is a very welcome addition to the Barclays board."
Earlier in her career, Francis spent 12 years at the Treasury before serving as private secretary to the Prime Minister.
Share price in Barclays, which has recently experienced a slide along with the rest of the UK's banking sector, is currently trading up 3.7 per cent at 132p at time of writing.