Pigeon pea (Cajanus cajan) is an important legume crop widely grown in India and other tropical regions, valued for its high protein content (20–24%) and role in food and nutritional security. Commonly consumed as arhar or tur dal, it serves as a staple pulse in Indian diets. The crop improves soil fertility through biological nitrogen fixation and enhances soil structure by adding organic matter. Its deep root system provides drought tolerance, making it suitable for marginal and rainfed areas. Pigeon pea supports sustainable and eco-friendly farming systems and performs well in intercropping with cereals and oilseeds. Besides providing nutritious food for humans, it also supplies fodder for animals, while crop residues are used as fuel and fencing material. Economically, pigeon pea contributes significantly to farmers’ income and rural employment. Overall, pigeon pea plays a vital role in sustainable agriculture, environmental health, and livelihood security.