The supermarket giant has signed up Tom Hoskin, currently deputy to Number 10 communications director Mike Ellam.
He will start in September as head of corporate media.
Hoskin is a former head of news at the Foreign and Commonwealth Office. He moved to Downing Street in July 2008.
As head of news at Number 10, he oversees the press office's handling of enquiries from journalists, organising of interviews for the Prime Minister and press attendance at events. Hoskin also handles lobby briefings when Ellam is unavailable.
At Tesco, Hoskin will report to director of media John Church.
Church said: 'As a growing international business, one of the things that really appealed to us about Tom was his background at the Foreign Office.'
Hoskin will not be the first former Downing Street aide to occupy a senior communications role at Tesco. The supermarket already employs Tony Blair's former private secretary David North as government affairs director.