President Lungu has also dropped deputy army commander Jackson Miti and a replacement is yet to be appointed.
Until his appointment, General Sikazwe, who has now been elevated to the rank of Lieutenant General, served as chief of operations.
Speaking during the ceremony at State House, President Lungu urged General Sikazwe to defend the Constitution and the people of Zambia.
President Lungu also told the new Army Commander to remind his officers on the need to respect the hierarchy of power.
He said the Zambia Army is well respected in Africa and expects that to continue even as the new Army Commander takes over.
The Head of State has also asked General Sikazwe to work with the outgoing Zambia Army Commander on various projects as he hands over.
And General Sikazwe promised to ensure that the President’s pronouncements are implemented.