Diabetes mellitus is a metabolic syndrome defined as a group of metabolic disorders that lead to elevated blood sugar levels. This chronic elevation is caused by a deficiency in insulin secretion, insulin action, or both, resulting in disturbances in the metabolism of carbohydrates, proteins, and fats. In recent years, diabetes has become increasingly prevalent. Chemically, pharmaceutical drugs are used to mitigate the effects of diabetes and its subsequent complications; however, these medications often come with undesirable side effects, such as weight gain, gastrointestinal issues, and heart failure. On the other hand, medicinal plants can serve as a valuable source of antidiabetic drugs. Dietary restrictions, physical activity, and the use of plant-derived antidiabetic compounds are promoted as effective and safe methods for diabetes management due to their lower cost and fewer or negligible side effects. Additionally, their bioactive components, chemical characterization, and plant-based diets play a significant role in managing both diabetes and cardiovascular diseases. These approaches can help develop future strategies, such as identifying promising bioactive molecules for diabetes treatment. Natural product-based therapies play a crucial role in treating various diseases, and medicinal plants can be used for the prevention and treatment of diabetes due to their phenolic compounds, many of which exhibit antioxidant properties. Interest in medicinal plants has grown recently, forming the foundation of what is now known as alternative or complementary medicine. This review focuses on antidiabetic and cardioprotective plants, aiming to identify the potential benefits of medicinal plants in the prevention and treatment of diabetes and cardiovascular diseases through safe, cost-effective, and alternative approaches.