The purpose of the study was to determine community socio-economic factors affecting students‟ academic performance in public Secondary schools in Rongo Sub-county, Migori County, Kenya. The study used descriptive survey research designs. The study was based on the conceptual framework. The targeted populations were 45 head teachers, 45 Guidance and Counseling teachers, 45(Parents Teachers Association (PTA) chairpersons, 14523 students, 5 Zonal Quality Assurance and Standards Officers (ZQASOs). The researcher used saturated sampling technique to select 45 head teachers, 45 Guidance and Counseling teachers, 45 PTA chairpersons and 5 ZQASOs, purposive random sampling was used to select 450 students. The instruments of data collection were questionnaires, in-depth interview, and document analysis. Reliability of the instruments was addressed through piloting in 5 schools and reliability coefficients were obtained by subjecting the instruments to a Split-half Technique and Spearman “Brown Prophesy formula”. The coefficient of reliability obtained was 0.721 which indicated that the instruments were reliable. To ensure face and content validity of the research instruments, 2 experts in the department of Educational Administration Planning and Economics, Kisii University were requested to scrutinize the research instruments so as to validate them. Data was analyzed using both qualitative and quantitative methods. Qualitative data was analyzed using likert scale and other qualitative data were analyzed in an ongoing process as themes and sub-themes emerged. Quantitative data was analyzed using descriptive statistics. The finding revealed that 25(62.5%) of Head Teachers agreed that community assist in the mobilizing students to go to school hence increase enrolment. It was concluded that the significant community socio-economic activities that promoted academic performnce were: School sponsorship, provision of piped and natural fountains of water,spiritual nourishment of students provision of physical facilities. It recommended that the schools should develop relations with the community to tap the full potentialities needed for academic performance. The researcher adhered to research ethics including plagiarism and getting the consent of respondents among others.