This study assessed the roles of the school heads as human resource managers in enhancing teachers’ job performance in public secondary schools in Kwimba district. It specifically explored the roles of the school heads as human resource managers. Also, established strategies to be used by the school heads as human resource managers to enhance teachers’ job performance. The study employed mixed research approach and convergent parallel design. The gathered quantitative data were coded and analyzed by using SPSS version 20 and presented through descriptive statistics such as tables, frequencies and percentages. Qualitative data were analyzed based on themes. The findings indicated that, roles such as teaching supervision, planning and placement of teachers, providing guidance and counseling, managing conflicts were seen to be carried out by the school heads. Also, school heads’ roles such as encouraging teamwork, creating safe working environment and teaching supervision were perceived to enhance teachers’ job performance in a highest level. The study also identified that, lesson preparation and teaching were seen to be enhanced by school heads’ roles. The respondents proposed that, in order to enhance teachers’ job performance, the school heads ought to provide motivation, involve teachers in decision making and maintain proper communication. The study recommends that, the government is required to increase financial budget to the public secondary schools, to provide seminars and special trainings to the school heads about management skills and lastly is that politics should be put aside from schools matters. By so doing, school heads as human resource managers will be capable to play their roles effectively and efficiently towards enhancing teachers’ job performance.