TEOS, or tetraethyl orthosilicate, is a versatile compound with various applications. It is commonly used as a crosslinking agent in silicone polymers and as a precursor to silicon dioxide in the semiconductor industry. TEOS is also utilized as a source of silica for synthesizing certain zeolites. Additionally, it finds use in coatings for carpets and other objects, as well as in the production of aerogel. These applications take advantage of the reactivity of the Si-OR bonds present in TEOS.

Furthermore, TEOS has a historical application as an additive in alcohol-based rocket fuels, significantly reducing heat flux in regeneratively cooled engines by over 50%. In the steel casting industry, TEOS serves as an inorganic binder and stiffener for creating silica-based ceramic molding forms. It can also be used as an inorganic binder for coatings, providing water, oxygen, and high-temperature resistance to materials like steel, glass, brass, and even wood. TEOS acts as an additive in solid polymers, enhancing adhesiveness to glass, steel, or wood surfaces. Moreover, it acts as a binder for porcelain teeth crowns and serves as a precursor to siloxanes, further expanding its range of applications.