Onimim Jacks was born on December 4, 1961 in Buguma, Asari Toru Local Government Area of Rivers State. She read Law at the University of Lagos and obtained a Bachelor of Laws degree in 1983, from where she also obtained a Masters in Law (LL.M) degree in 1991.
In 1984, she was called to the Nigerian Bar and enrolled as a Barrister and Solicitor of the Supreme Court of Nigeria. She would later in 1987 become an Attorney and Counselor at Law of the State of New York in the United States of America. Onimim had a short Legal Practice in the United States of America between 1986 and 1987 as a Volunteer Attorney in the Civil Division of the New York City Legal Aid Society in Chelsea, New York. In that capacity, she represented indigent citizens in housing matters before the Housing Court as well as in all other civil matters.
Upon her return to Nigeria, in 1989 as Managing Partner, she set up private Legal Practice in Lagos and Port Harcourt under the name Onimim Briggs & Co. The firm specialised in Commercial Practice in the Banking and Oil and Gas sectors. It also conducted pro bono criminal defenses for indigent persons.
Her enduring passion for education would see her take up a Lecturing appointment at the Nigerian Law School Abuja in 1998 where she invested 10 years of her life lecturing Criminal Law Procedure, Legal Skills and along with others, developed course contents and enhanced teaching methods.
Until recently, she was Executive Director of the Legal Research Institute, Abuja. In that capacity, she was responsible for the coordination of researches in different areas of law, publishing legal findings, training of lawyers in research methods and other legal skills, compilation of laws and judgments for case reporting, collaboration with international agencies in the promotion of legal education and the consultation for the Legislature by conducting research and drafting bills.
As Chief Legislative Officer in the office of late Senator Martins-Yellowe between 2001 to 2007, she was responsible for preparing bills, perusing and advising the Senator on legislative matters.
In 2009, she was appointed Sole Administrator of the Rivers State Library Board with the mandate of further developing the Library System and overseeing all libraries within the State. It was her last pubic assignment until her recent appointment by the Governor of Rivers State, His Excellency, Chief (Barr.) Nyesom Ezewon Wike, CON, as the Rivers State Commissioner of Agriculture.
Mrs Onimim Jacks has published a number of articles and journals and has attended many conferences around the world. She is a member of the Nigerian Society of International Law, International Law Association, Nigerian Institute of International Affairs, Nigerian Bar Association, American Bar Association, Federation of International Women Lawyers (FIDA), International Bar Association and the International Society for the Reform of Criminal Law