Dr Christopher Cheok is the Vice Chairman, Medical Board (National Addictions Management Service), Institute of Mental Health. He is a Senior Consultant psychiatrist and a visiting consultant to the Singapore Armed Forces and Khoo Teck Puat Hospital. He is also a member of the medical board of the Civil Aviation Authority of Singapore.
During his career with the Singapore Armed Forces, Dr Cheok was the Commanding Officer of Medical Classification Centre, the Deputy Commander of the Military Medicine Institute and the Head of the Psychological Care Centre. He has served in peacekeeping missions in East Timor and humanitarian relief mission during Indian Ocean tsunami of 2004.