The purpose of this study was to determine the mediating effect of English speaking skills (ESS) on the relationship between social literacy (SL) and student engagement (SE) among English major education students in the private Higher Educations Institutions (HEIs) in Region XI. By which, the study used a sequential explanatory mixed methods research design having a total of 300 English major students from the different private tertiary institution in Region XI as the research respondents. For the data analysis, medgraph was employed in determining the mediating effect of ESS on the relationship between SL and SE which was found to be significant partial mediation in this study. Then, through interviews and focus group discussion with 17 participants taken from the quantitative respondents, data were integrated with the findings in the quantitative aspect of the study. The participants confirmed the relationships and the functions of the variables in the mediation model. With the confirmation, it can be gleaned that there is substantial evidence that ESS is one of the reasons why SL could influence SE among English major students in the private tertiary institutions in Region XI as demonstrated in the partial mediation model. Thematic analysis of the qualitative data unveiled the essential themes generally confirming the connecting-merging-confirmation surfaced as the nature of data integration.