File Photo: Saudi Crown Prince Mohammed bin Salman on July 28, 2022. AFP
Mohammed bin Salman, was previously serving as deputy prime minister under King Salman as well as defence minister.
He is being replaced as defence minister by his younger brother, Khalid bin Salman, who was previously deputy defence minister.
The heads of other critical ministries, including interior, foreign and energy, remained in place, according to a royal decree from King Salman published by the official Saudi Press Agency.
Prince Mohammed, who turned 37 last month, has been first in line to succeed his father as king since 2017.
He became defence minister in 2015, a key step in a swift consolidation of power that saw him take the lead on major portfolios.