An effective system of governing is crucial for advancing both social and economic development, with a focus on promoting openness, accountability, and active involvement of the people. Public participation entails the active involvement of citizens in the process of governance, promoting openness, responsibility, and fair provision of public services. This method facilitates well-informed decision-making and improves governance by ensuring that policies align with the requirements and priorities of the community. To enhance efficacy, numerous governments have transitioned from centralization to decentralization, thereby enabling local governments to include citizens more directly in the process of decision-making. The Constitution of Kenya 2010 incorporated decentralization and public involvement as integral components to enhance governance in Kenya. Nevertheless, despite extant literature suggesting that leadership affects participation, the extent to which various leadership styles impact the effectiveness of public engagement has not been well investigated. This study examines the influence of transactional leadership style on the effectiveness of public participation in the county governance in Kenyan. The components of transactional leadership styles consisted of contingent reward, contingent punishment, Management-by-Exception-active, and Management-by-Exception-passive. The study adopted a positivist philosophy, using scientific methods to explore social phenomena, focusing on objectivity and empirical verification. The research used a quantitative survey design, with questionnaires for data collection. The analysis involved devolved county governments, targeting residents from eight counties, who had engaged in public forums. A sample of 400 respondents was obtained through both probabilistic and non-probabilistic sampling methods. The results of the regression analysis indicated that there was a positive relationship between transactional leadership and the effectiveness of public participation. The implementation of active management-by-exception and contingent incentive resulted in a notable increase in public engagement, with active management-by-exception having the most prominent influence. The effects of contingent punishment and passive Management-by-Exception were positive, although they failed to achieve statistical significance. The study recommends county authorities to prioritize active management-by-exception and use reward schemes to enhance public participation. Additionally, it suggested implementation of training programs aimed at transforming executives from passive to proactive management approaches. In addition, proposals were made for policies that support leadership training and civic education to promote public participation. This study enhances the existing theory by empirically demonstrating the relationship between transactional leadership style and the effectiveness of public participation. It also offers a foundation for future research in this area. Subsequent investigations should examine additional variables that impact the efficacy of public participation in county governance, considering cultural and contextual variations.