Nudge theory in behavioural economics explores how subtle changes in the environment can significantly influence decision-making. This concept highlights the impact of small adjustments on behaviour, helping individuals make better choices without restricting options. As businesses and policymakers recognize the power of nudges, applications in areas like health, finance, and education are becoming more prevalent. Understanding the nudge theory can enhance strategies for promoting positive behaviours and improving overall outcomes. This article delves into the principles of nudge theory and its real-world implications, providing valuable insights for economists, marketers, and decision-makers.