A new Department of Youth Justice will be created and led by one of Queensland's most senior police officers amid an unfolding crisis involving children being held in adult watchhouses.

Premier Annastacia Palaszczuk announced the measure on Friday, following a week of heavy criticism over detention of children in maximum security cells built for adults, some for weeks at a time.

Deputy Police Commissioner Bob Gee has been announced as the director-general of the Department of Youth Justice. Credit:AAP/Dave Hunt.

Deputy Commissioner of Police and State Disaster Coordinator Bob Gee has been appointed as director-general of the department, and will start in his new role on Monday.

He said he wanted to get children out of watchhouses as soon as possible but could not say when that would be achieved.