Chief Koleoso was born on April 30, 1938, into the Emi-Abata family of Saki. He completed his elementary schooling at Baptist Primary School in Ajegunle, Saki, and then went on to the renowned Olivet Baptist High School in Oyo, where he attended from 1957 to 1961.
After earning his Ordinary National Diploma (OND) at the School of Hygiene, Eleyele, Ibadan, he went on to complete his Advanced Certificate (RSII), which is now the equivalent of an HND, in 1965 and 1966.
As Head of the Health Department of the former Saki District Council, Koleoso began his career in the Western Region civil service.
After spending many years in service he ventured into business. His initial business, Esmak Nigeria Limited, is still in operation today and is primarily focused on the distribution of commodities, real estate, transportation, and hospitality..
Pa Koleoso was elected unopposed as Councilor in Ifedapo Local Government Area of the Old Oyo state in 1976.
In 1979, he got elected into the Oyo State House of Assembly as the representative of Ifedapo Constituency on the platform of the Chief Obafemi Awolowo-led Unity Party of Nigeria (UPN)
He served as SSG during the late Governor Lam Adesina-led administration.
He was the National Chairman of the defunct Alliance for Democracy.
