The influential mathematician noted for their work on game theory is John von Neumann. His pioneering contributions in the early 20th century established game theory as a fundamental framework for analyzing strategic interactions among rational decision-makers. Von Neumann's work laid the groundwork for various applications, including economics, political science, and biology. His insights on cooperation, competition, and optimal strategies significantly advanced our understanding of complex systems. Game theory remains a vital tool in numerous fields, illustrating the balance between strategy and outcomes in competitive scenarios.