She will report directly to Dr Richard Barker, director general of the ABPI and will be a member of the senior leadership team.
In her new role, Callaghan will be responsible for supporting the ABPI board, director general and senior leadership team in all aspects of communications.
Dr Barker said: 'We are fortunate to have such an accomplished healthcare communicator able to take the profile of the industry and the ABPI to new levels.'
In January, Alison Clough was promoted to commercial and communications director at the ABPI after director of corporate comms David Lewis left the company.
Clough will continue to handle the commercial aspects of her role.