Mr Sants left the FSA in June after five years as chief executive when the regulator was split into a twin-peaks model.
His new role at Barclays will be head of compliance and government and regulatory regulations. He will also join the executive committee.
Within this role, he will oversee all Barclays' compliance activities and will mean, for the first time, all compliance staff across all Barclays regions will report to one individual. He will also take on responsibility for Barclays' relationship with governments and regulators worldwide.
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Mr Sants said: "I left the FSA with the intention of finding a role which would allow me to put into practice the experience I have gained in both the public and private sector. Taking on responsibility of leading Barclays global compliance function and overseeing the bank's relationships with governments and regulators gives me that opportunity."
Antony Jenkins, group chief executive for Barclays, said: "In appointing this new senior role and making these structural and reporting line changes, I want to do two things. The principal one is to create the conditions whereby a world class compliance function can flourish and the second is to send a clear signal of intent in terms of my personal commitment to delivering a culture in Barclays where compliance is universally welcomed and observed."
Mr Sants will take up his new role on 21 January 2013

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