This study investigated the influence of school leadership on teachers’ motivation in secondary schools in Morogoro, Tanzania. A mixed-methods approach combined quantitative data from 69 teachers and qualitative insights from 8 heads of schools purposefully selected from public and private institutions. Data were collected through online questionnaires and Key-Informant Interviews (KII) and analyzed using the Statistical Package for the Social Sciences (SPSS) with linear regression. Findings revealed a statistically significant positive correlation between school leadership and teacher motivation. In private schools, leadership predicted teacher motivation more strongly (β = 0.779, p = 0.001) than in public schools (β = 0.680, p = 0.001). Qualitative results confirmed that recognition, participative decision-making, and professional development enhance motivation, whereas inadequate resources constrain public-school morale. The study concludes that effective, participatory leadership is critical for teacher motivation and recommends leadership-training programs, supportive policy environments, and longitudinal research on the link between leadership and teachers’ job satisfaction in Tanzania.