This study's main objective was to examine the relationship between various leadership styles and employee productivity at Kenya's Rural Electrification and Renewable Energy Corporation (REREC). The research intended to evaluate the effect of transformational leadership styles on employee output at REREC, utilizing four leadership approaches: situational, participative, transformational, and transactional leadership. The research was structured around three theories: the path-goal theory, situational leadership as proposed by Hersey and Blanchard, and Keller's ARCS model of motivation. A descriptive survey methodology was employed. The study involved 199 participants from the Finance, Human Resources, Operations, Technical Services, Planning, and Procurement divisions at REREC's headquarters in Nairobi County, as well as interviews with six top managers from these divisions. A census sampling approach was used to select all 199 respondents. Both closed- and open-ended surveys were utilized, and SPSS version 26 software was used for quantitative analysis. The investigation determined that transformational leadership exhibited the highest positive correlation with employee performance (r = 0.75) and was the most significant predictor (β = 0.45, p < 0.01). Participative (r = 0.72) and situational (r = 0.70) leadership styles also demonstrated strong positive impacts on performance. Transactional leadership had a moderate correlation (r = 0.68) and was effective in structured environments but less impactful for driving long-term innovation and satisfaction. The study concluded that integrating multiple leadership approaches tailored to organizational contexts is crucial for maximizing employee performance. Transformational leadership, fostering motivation and engagement, emerged as the most effective style at REREC. Recommendations included implementing leadership development programs, enhancing employee engagement strategies, adopting data-driven leadership approaches, and continuously adapting leadership models to align with evolving workplace trends.