The Yang di-Pertuan Agong will grant Dr Mahathir Mohamad an audience at 5pm.
The secretary-general of Pakatan Harapan, Saifuddin Abdullah, told Reuters that Mahathir will be accompanied by four other leaders from the coalition when he meets the king.
Earlier, Mahathir said he expected to be sworn in as prime minister today.
Pakatan Harapan won a simple majority in Wednesday’s polls, defeating the long-ruling Barisan Nasional coalition.