Prime Minister Scott Morrison announced on Friday morning that Andrew Shearer, a long-serving diplomat and security advisor, would take over as the director-general of the office.

"I am pleased to announce that I intend to recommend to the Governor-General Mr Andrew Shearer as the new Director-General of the Office of National Intelligence (ONI)," Mr Morrison said in a statement.

"Mr Shearer has served Australia and its national interests domestically and overseas through a long and distinguished career in national security and intelligence."

Mr Shearer previously served as a senior national security adviser to both Tony Abbott and John Howard during their prime ministerships. He has also served as the Office of National Assessment's deputy director-general and as a senior diplomat at Australia's Washington embassy.

He will start his five-year posting in December.

It comes two weeks after former ONI head Nick Warner announced he would be retiring in December after three years in the role.

"Mr Warner's expertise and distinguished career is without peer, and he has well-served our government and our nation, including his role at ONI and as Director-General of the Australian Secret Intelligence Service," Mr Morrison said.

The ONI forms a part of Australia's 10 national security agencies, collating intelligence collected by other agencies and providing assessments to the Prime Minister and National Security Committee.