Saudi King Abdullah bin Abdel Aziz appointed the kingdom's veteran Interior Minister Naif bin Abdel Aziz as crown prince, reported the state news agency.
The agency added that the appointment followed a meeting between the Saudi monarch and the Allegiance Authority, a council he set up in 2007 to select the oil-rich country's king and crown prince, DPA reported.
Naif's appointment comes six days after the death of his predecessor and brother Sultan bin Abdel Aziz in a New York hospital.
Naif, 78, has been the kingdom's interior minister since 1975 and became a second deputy prime minister in 2007.