Abstract: The purpose of this study was to investigate the effect of an instructional program based on the implications of John Hattie's visible learning on enhancing college students' oral fluency skills. Thirty 1^st year students enrolled in STEM program at the Faculty of Education, Ain Shams University, participated in the study which took place in the 1^st semester of the academic year 2021-2022. The study utilized a mixed-methods approach. A pre/post oral fluency test was administered to the participants prior to implementing the suggested instructional program. Then, an instructional program based on the implications of visible learning developed by the researchers was taught to the participants. The oral fluency test was post administered and the participants were asked to respond to a satisfaction questionnaire. Quantitative data was collected from the students' scores in the pre/post tests and was analyzed using the convenient statistical techniques. Qualitative data, on the other hand, was collected from the Students' Satisfaction Questionnaire. Findings of the study indicated the effectiveness of the proposed program in developing participants' oral fluency skills as a whole and in separation. Findings of the study are discussed and recommendations for further research are stated.