Maleic acid is widely used in the production of polymers and resins, particularly in the manufacture of alkyd resins, which are essential for paints and coatings. Its ability to form copolymers makes it valuable in creating materials with enhanced durability and chemical resistance.

In the agricultural sector, it serves as an intermediate in the synthesis of various pesticides and herbicides, contributing to effective crop protection. Additionally, it is utilized in the textile industry as a dyeing and printing auxiliary, improving the quality and colorfastness of fabrics.

Maleic acid also plays a role in the food industry as an acidity regulator and flavor enhancer, particularly in beverages and processed foods. Its chelating properties make it useful in water treatment processes, where it helps to remove metal ions and prevent scaling in industrial systems.

In pharmaceuticals, it is employed in the production of certain drugs and as a stabilizer in formulations. Its versatility and reactivity make it a key component in various industrial and commercial applications.