Prof. Okelo is a pure mathematician by profession and prolific researcher in mathematical sciences and applications to other fields. His research interest is in functional analysis, particularly, operator theory. His research and professional career has been centered on mathematics and applications to other fields like business, economics, education, and agriculture and food security among others. Currently, his research is on Hilbert space operators and their applications to petroleum technology and utilization of solar energy. He has produced more than 30 publications in internationally refereed journals and was ranked amongst the top young scientist in 2013 by AU-TWAS. He endeavours to mentor young scholars who aspire to become researchers. He endeavours to do research that has applications to other areas like Quantum Mechanics; Mathematical Modelling and Analysis; Contemporary Issues in Special Needs Education; Business and Economics; Computing and Information Technology. The output of his research is for solving real life problems of socio-economic nature in Kenya (and other developing countries), Africa and Globally. Currently at Jaramogi Oginga Odinga University of Science and Technology (JOOUST).