Biostimulants, a promising avenue in agriculture, are substances that significantly enhance plant growth and productivity. They are a rich source of various compounds and microorganisms, including humic substances, amino acids, seaweed extracts, chitin and chitosan polymers, inorganic compounds, seed and root extracts, and organic wastes. Humic substances derived from decomposed organic matter are crucial in improving soil structure and nutrient availability. On the other hand, amino acids and protein hydrolysates promote nitrogen uptake and stress resistance, enhancing plant growth. The rich in polysaccharides and phytohormones, seaweed extracts enhance root development and stress tolerance. Polymers such as chitin and chitosan, derived from crustaceans and fungi, provide protective effects against pathogens and environmental stressors. Inorganic compounds and plant extracts also contribute to growth and resistance. The growing global biostimulants market is a testament to the increasing demand for environmentally friendly agricultural solutions, highlighting the urgency of adopting these solutions. Unlike traditional fertilizers, biostimulants do not directly provide nutrients but improve how plants use available nutrients more efficiently. Research underscores the potential of biostimulants to contribute to sustainable agriculture by increasing yield, quality, and disease resistance. Indispensable in modern agriculture, biostimulants are the key to creating sustainable and productive agricultural systems with more resilient plants by stimulating the development of crops, especially under unfavorable conditions, and improving crop quality.