"head department" is correct and usable in written English.
You can use it to refer to the department in a company that is in charge of other departments, as in the example sentence: "The head department of the company decided to implement new safety measures."
Head, department of public health and policy, Institute of Psychology, Health and Society, University of Liverpool.
SUBRA SURESH, professor and head, department of materials science and engineering, Massachusetts Institute of Technology, Cambridge.
FRANK S. BATES, professor and head, department of chemical engineering and materials science, University of Minnesota, Minneapolis.
COOVADIA, Hoosen M.; professor and head, department of pediatrics and child health, University of Natal, Durban, South Africa.
ROBIN M. MURRAY, professor and head, department of psychiatry, Institute of Psychiatry at the Maudsley, King's College London.
Further approval was obtained from the head Department of Hematology for the conduct of the study within the blood bank unit which was under their jurisdiction.
He trained more than 60 neurosurgeons, many of whom went on to head departments at medical schools across the country.
And of course, in the hair-on-the-head department, though she's recently been rocking various lengths and colors of dreadlocks, Miley has followed Nick in taking the shorter road.
So… the three of us have been here for a while… So, well-known to the department division heads, department heads, whatever you want to call it.
Improvement would also result from a closer liaison between departments at the head of department level.
The respondents were at the level of head of department, deputy head of department, chief director or senior consultant in the national or provincial departments of health and deans, vice-deans, heads or senior academic of medical schools.
