Adedeji has an MBA from Abubakar Tafawa Balewa University after graduating from the Lagos State Polytechnic with a Higher National Diploma in Insurance. He started his work life as a Marketing/ Reinsurance Manager at Safeway Insurance Company Limited in 1983 from where he proceeded to Financial Assurance Limited in 1990. He became the Kaduna Branch Manager of AIICO Insurance PLC in 1992 and retired with merits in 2006. He joined Marvelous Insurance Brokers in 2006 as an Executive Director growing the Lagos office and the entire southern Part of Nigeria.