Polycystic ovary syndrome (PCOS) is one of the most prevalent endocrine disorders among reproductive-aged women. It is characterized by hyperandrogenism, anovulation, and polycystic ovaries. Lifestyle changes are suggested as first-line interventions in managing PCOS. This systematic review aims to assess the scientific evidence regarding the role of lifestyle modifications (dietary changes, physical activity, and behavioral changes) in improving reproductive, anthropometric, metabolic, and psychological outcomes in women with PCOS. Dietary interventions such as foods with low glycemic index scores; caloric restrictions; high-fiber, omega three fatty acid-rich diets; ketogenic diets; Mediterranean diets; antioxidant-rich food; and anti-inflammatory diets improve insulin sensitivity and hormonal balance in women with PCOS. Physical activity, like aerobic and resistance exercise, enhances insulin sensitivity, helps weight loss, and improves metabolic and reproductive outcomes in women with PCOS. Further, behavioral and education modules can also be used to improve awareness, adherence, and the effectiveness of conventional treatment and to manage mental health issues related to PCOS. Collectively, lifestyle modifications not only improve the biochemical, hormonal, and anthropometric parameters in PCOS patients but also reduce the long-term risks of metabolic and cardiovascular diseases.