Otunba Onabanjo began his career as a General Manager at Nigeria Motors Industries (a division of CFAO PLC) in 1977 and within 2 years he was appointed the General Sales Manager, a position that endeared directors of the company due to his excellent performance. Also, he was sponsored by the company to attend the West African Sales Management Course at Berris St. Edmund and Columbia Graduate School of Business, New York, for Executive courses in sales management in 1978 & 1979 respectively.
In 1981, Onabanjo left NMI to become the Managing Director of Quality Printing and Paper Company Limited in Ilupeju, Lagos and remained there until 1989 when he resigned to set up his company and become a more active participant in the private sector.
He joined other Nigerian entrepreneurs to form several companies where he served as a member of board of 15 corporate organisation’s. Later on he established PSG Exploration Nig. Ltd. in partnership with a Norwegian company and Nigeria’s NNPC.
Alex Onabanjo has substantial investment in Oil and Energy companies, serving oil companies through strategic alliance with technical partners around the world.
Otunba Onabanjo is also an icon of social and philanthropic services with diverse interest, covering many areas including Education, sports, culture, and voluntary organizations.
While he was the Director of International Services of the Rotary Club of Surulere, a Paul Harris Fellow and Five Star General in Rotary International, he contributed in various ways to the betterment of the society by endowing numerous prizes in Business Administration and Physical Sciences disciplines in various Nigerian universities.
The most significant contribution he made in the education sector is the endowment of Geological equipments worth N200 million to the Department of Earth Sciences in Ogun State University Ago-Iwoye in 1999 and N227million Otunba Alex Onabanjo Petrochemical Science Laboratory and Office Complex at Tai Solarin University of Education, Ijagun Ogun State in 2007.
Another contribution made was his donation of an Auditorium and a Senior Staff Canteen to Tai Solarin University Of Education. Also, he donated an Electronic Library with 500 Computers and 2 powerful generators as well as built and donated a Student Union building.
In 2020, to celebrate his 70th birthday, Alex Onabanjo built and donated an Academic Staff Building at the Abraham Adesanya Polytechnic Ijebu Igbo and donated an Auditorium and a Senior Staff Canteen to Tai Solarin University Of Education.
In 2018, he suffered an abrupt end to his marriage of 40 years. Onabanjo and his wife were a model couple to their children, business associates, family and friends. Everybody wished for their kind of wedlock as the affluent couple radiated infectious love and companionship. It was therefore a shock to their loved ones when the news broke out. However, he rediscovered bliss in Kunle Bakare.
Alex Onabanjo is Otunba Sakinmolu of Ago-Iwoye (1984) and Aro Oba of Ago-Iwoye (1994).