Davidge, who takes up the newly created post on 19 July, will be expected to thrash out a media relations strategy for the campaign before its launch in January 2005.
Scientists, politicians, universities and members of the public will be targeted via main news outlets and the scientific press.
Davidge, who was head of PR at Macmillan Cancer Relief for three years, will report to Cancer Research UK executive director in charge of policy and communications Robert Souhami and lead a team of 23.
As the charity's top PRO, her remit includes responsibility for communications to the media and external PR agency appointments.
'We want the public to know how the money they have donated is being spent on world-leading science, how we are making progress and what new clinical improvements are available as a result of our fundraising,' said Souhami.
He added that the January campaign would be a 'departure' for the organisation: 'We aim to increase our activity in the area of cancer prevention to make certain we are banging this particular drum.'
The Medical Research Council is currently on the hunt to replace Davidge.