Born in 1956 in Akuku-Toru, Rivers State, Ajumogobia holds law degrees from the University of Lagos (1978) and Harvard (1988). He lectured at Lagos University before founding his own practice, Ajumogobia and Okeke, in 1984, his practice areas include: Commercial litigation and arbitration; Environmental Law and oil pollution litigation; Transportation law with a specific interest in Aviation Law. Recently he was appointed as a member of the ICC International Court of Arbitration, Paris.
Ajumogobia became a Senior Advocate of Nigeria in 2003, and was appointed Attorney General and Commissioner of Justice for Rivers State in 2003. Ajumogobia is a Member, Council of Legal Education; Member Executive Committee of NBA; Member, Body of Benchers (2003- 2007); Chairman, Rivers State Sustainable Development Agency (2005-2007); Minister of State for Energy (Petroleum) and Head of Nigeria's Delegation to OPEC (July 2007-December 2008).
He was appointed Minister of State of Petroleum Resources and Supervising Minister Ministry of Power and Head of Nigeria's delegation to the Gas Exporting Countries Forum (GECF (January2009-March 2010); Member National Economic Council; Member, Honorary Investment Council; Member, National Privatisation Council; Member, National Independent Power Programme; (2007- 2010) Minister of Foreign Affairs (April 2010 - May 2011): Member, National Security Council, President UN Security Council (2010) Chairman Council of Ministers of Ecowas States; Co- Chairman (with H.E. Miguel Angel Moratinos Cuyaube- Minister of Foreign Affairs and Cooperation of Spain of Political Dialogue between EU and ECOWAS Luxembourg (2010); Co-Chairman (with H.E. George Rebela Chicoti Minister of Foreign Affairs of Angola), International Contact Group on Guinea Bissau at UNGA (September 2010).
Odein Ajumogobia is an Ijaw (Kalabari) from Abonnema in Rivers State. He is married to Awuneba Ajumogobia FCA (née Iketubosin) also from Abonnema, Rivers State. They have a son and three daughters. Ajumogobia also has wide musical interests including – the piano, organ and voice; and he has recently taken up the guitar and saxophone; he is a keen chess, squash and table tennis player.
His publications include: Chapters in Aircraft Finance, Registration Security & Enforcement ed. Mcbain & Hames (Longman 1990); Aircraft Liens and detention rights ed. Graham S. McBain (Sweet & Maxwell 2001); Contributor to WIPO publication "Preparation of Franchising Guide for Developing Countries; Enforcement of Foreign Judgements; edited by Louis Garb and Julian Lew(Kluwer); International Product Liability (Aspatore 2004).