Type 2 Diabetes Mellitus (T2DM) is one of the most prevalent chronic metabolic disorders worldwide and represents a major public health challenge. Characterized by insulin resistance and progressive pancreatic β-cell dysfunction, T2DM is associated with significant morbidity, mortality, and healthcare expenditures. Lifestyle factors including unhealthy dietary habits, physical inactivity, obesity, smoking, and stress play critical roles in the development and progression of T2DM. Consequently, lifestyle interventions have emerged as essential components of diabetes prevention and management strategies. This study reviews the impact of lifestyle interventions on glycemic control, body weight, cardiovascular risk factors, and quality of life among individuals with T2DM. Through a comprehensive review of current literature, clinical guidelines, and landmark intervention studies, the paper highlights the effectiveness of dietary modifications, physical activity, weight management, behavioral therapy, and digital health technologies in improving diabetes outcomes. Findings suggest that sustained lifestyle interventions significantly reduce HbA1c levels, improve insulin sensitivity, decrease cardiovascular complications, and enhance overall well-being. The study concludes that integrating evidence-based lifestyle interventions into routine diabetes care is crucial for achieving long-term disease control and reducing the global burden of T2DM.