The achievement gap stands as one of the top priorities framing educational policy through the past half-century. The middle school level amplifies this gap especially in urban areas. The role of principal leadership in closing the achievement gap is key. The purpose of this study was to examine the relationships between the leadership styles of principals assigned to Title I middle schools, staff longevity, school climate, and overall school achievement. The researcher applied a non-experimental, ex-post facto research design to investigate the research hypotheses. Utilizing the Google Survey Platform, 290 staff members across 30 middle schools within a large urban school district in southeast Florida, completed a survey which included questions related to longevity, and the Multifactor Leadership Questionnaire (MLQ Form 5x). Results of the school district’s School Climate Survey, Staff Form, were employed to gauge school climate. Hierarchical linear regression analyses revealed several significant positive associations between transformational leadership and numerous of the academic areas explored (e.g., reading learning gains of the lowest quartile, math proficiency, and social studies proficiency). In contrast to what was predicted, transactional leadership, also positively predicted some of the academic achievement factors evaluated (e.g., math proficiency, and math learning gains). Staff longevity negatively predicted school grade. Staff climate positively predicted math proficiency, and math learning gains. On the other hand, staff climate negatively predicted school grade, the three factors related to reading achievement (e.g., proficiency, learning gains, and learning gains of the lowest quartile), and social studies proficiency. New research questions arose as a result of the investigation. Further research is recommended that examines the leadership variables explored within a larger sample, and in other geographical areas with similar demographics. As well, additional research is suggested involving staff longevity and school climate alongside a measure of collective instructional efficacy where urban schools are concerned.