Sadler will join in August, reporting to deputy chief constable Charles Clark.
Her main role will be to co-ordinate the four units within the media and PR department: the press office, publications, TV and PR teams. 'I want to work with the local community and local partners in public service to join up what we do and communicate it better,' said Sadler.
Her precise brief will be decided next week at a meeting with the force's new chief constable, Richard Baker, who joins from North Yorkshire Police this week.
Sadler replaces Angeline Burton, who left in April to join the City of London police as head of media and PR.