Some big moves are afoot at the top of Federal Government departments.

Reports say Kathryn Campbell will become the new head of the Department of Foreign Affairs and Trade in a shake-up of top public service roles.

Former vice-chief of the Defence Force, Ray Griggs, will replace Ms Campbell as secretary of the Department of Social Services.

Mr Griggs is moving across from leading the National Indigenous Australians Agency as its inaugural chief executive.

It is part of a reshuffle triggered when Frances Adamson left Foreign Affairs and Trade to take the role of governor of South Australia, and Chris Moraitis left the Attorney-General's office to become the leader of the Office of the Special Investigator earlier this year.

The new appointments will be for five years, following the Governor-General's acceptance of Mr Morrison's recommendations. 

Families and Social Services Minister Anne Ruston has praised Ms Campbell for “a decade of extraordinary service to social services”.

The Prime Minister noted Ms Campbell was also the first woman appointed to the rank of Major General in the Army Reserve, and has “an outstanding record in public service”.