The study explored teacher-leadership exemplified by the teacher-leaders of the member-institutions of the St. Paul University System (SPUS) and developed a Paulinian teacher-leader model. Specifically, it sought to answer questions such as (1) how teacher-leaders were identified; (2) how the teacher-leaders of the member-institutions of the SPUS performed in the three categories – instructional leadership, internal organization leadership, and external organization leadership; (3) what the significant accomplishments of the teacher-leaders of the member-institutions in the three categories were; and (4) what model of a Paulinian teacher-leader may be developed as benchmark points for the improvement of teacher leadership of the SPUS. Using the mixed design, quantitative instruments helped reach a complete understanding of the teacher leadership in SPUS, based on the 4Ps: professional competence, professional practice, professional leadership, and professional ethics and values in the five member institutions of SPUS, while the qualitative method helped reach a concrete definition. The participants had been purposefully selected to proceed to the second phase of the selection process. A survey questionnaire was used, results of which were scored quantitatively, and the responses to informal interviews using the guide questions strengthened the information gathered from the quantitative data. Hence, the best mix of the filtered responses from both research approaches was very useful in framing the structural model of a Paulinian teacher-leader. This study involved the participation of the full -time faculty members of the selected member-institutions of the SPUS all over the Philippines namely St. Paul University (SPU) Quezon City; SPU Manila; SPU Iloilo; SPU Dumaguete; and SPU Surigao. Cross-analysis of the data revealed that most of the teacher-leaders in the five selected SPUS member-institutions manifested ―strong teacher leadership‖ in the areas of instructional leadership, internal organization leadership, and external organization leadership. From the data gathered, the researcher was able to draw a Paulinian Teacher Leadership Model (PTLM).