Artificial Intelligence is rapidly transforming contemporary Project Management practices by enabling advanced Decision Support Systems that enhance data-driven managerial processes. This study examines the impact of AI-Based Decision Support Systems on Managerial Effectiveness in project environments, with particular attention to planning, risk forecasting, and Resource Allocation. Drawing on survey-based empirical evidence, the research evaluates how Predictive Analytics and intelligent automation influence decision accuracy, speed, and consistency. The findings indicate that AI-enabled Decision Support Systems significantly improve managerial insight by processing large-scale project data and generating actionable recommendations. However, the study also identifies practical limitations, including overreliance risks and the continuing need for Human-AI collaboration in complex project contexts. Overall, the research demonstrates that Artificial Intelligence functions most effectively as a strategic decision-support partner rather than a managerial replacement, offering practical implications for organizations seeking to strengthen Project Management performance through data-driven innovation and evidence-based managerial practices across dynamic and technology-intensive project environments worldwide today. These managerial insights provide a structured foundation for future empirical investigations and guide practitioners in responsibly integrating AI-driven tools into everyday managerial workflows without undermining professional expertise or contextual decision-making quality within modern project-based organizations operating under conditions of uncertainty and competitive pressure globally today and beyond.