Tributylphosphite is an organophosphorus compound with the chemical formula (C4H9O)3P. It is a clear, colorless liquid with a faint odor. It is commonly used as a stabilizer and antioxidant in the production of various polymers, including polyesters and polyurethanes. Additionally, it serves as a reagent in organic synthesis, particularly in the manufacture of pharmaceuticals and agrochemicals. Due to its versatile applications, tributylphosphite is an important intermediate in the chemical industry.