Professor Badejo holds a Bachelor of Science Degree in Biology, a Masters of Science in Zoology as well as a Doctorate in Zoology from Obafemi Awolowo University, Ile-Ife. In addition to these degrees, he also earned a distinction in the Post-Doctoral Diploma course in Environmental Science and Technology of the International Institute for Hydraulic and Environmental Engineering (IHE), which is now known as UNESCO-IHE in Delft, The Netherlands - an acknowledged European Centre of academic excellence.
He started his career in the University of Ife as a Graduate Assistant in 1981 and rose through the ranks to become a Professor in 1998. During this period, He has made significant contributions to the development and teaching of courses in Entomology, Ecology and Invertebrate Zoology in the Department of Zoology. As a member of the Faculty Board of examiners, he has been involved in the assessment of written examinations and students research projects at undergraduate and postgraduate levels.