Legionella spp. are opportunistic waterborne pathogens commonly found in artificial water systems, posing a significant risk of Legionnaires' disease, particularly in healthcare facilities, hotels, and other public infrastructures. High-risk environments with complex plumbing systems, such as hospitals and resorts, require proactive strategies to monitor and control Legionella proliferation. This study presents the integrated approach used by our laboratory to assess and manage the risk of Legionella contamination in various environments, with a focus on minimizing public health hazards. Environmental sampling was conducted across multiple high-risk sites including hospitals, hotels, and wellness centers. Water samples were analyzed using accredited culture-based techniques (ISO 11731:2017) for Legionella spp. detection and quantification. Risk assessments were conducted following national and international guidelines (e.g., NPHO, WHO, ECDC), incorporating site-specific factors such as water temperature, system design, and historical contamination data. Customized mitigation strategies were developed, including thermal disinfection, biocide treatment, and infrastructure improvements. Our surveillance identified Legionella presence in over 30% of sampled sites, with higher prevalence in older and poorly maintained systems. The implementation of targeted risk management plans led to a significant reduction in Legionella counts and an improvement in water system safety profiles over a 6–12 month follow-up period. A laboratory-driven, risk-based assessment model is essential for effective Legionella control in high-risk environments. Regular monitoring, continuous training of involved personnel, data-driven interventions, and close collaboration with facility management are key components in reducing infection risk and ensuring compliance with public health standards.