Chlorodimethyl(octadecyl)silane is widely used as a surface modifying agent to impart hydrophobic properties to various materials. It is commonly applied to glass, silica, and other oxide surfaces to create water-repellent coatings. This chemical is particularly valuable in the production of hydrophobic glass for automotive and architectural applications, where it helps prevent water spotting and improves visibility during rain.

In the field of chromatography, it is used to modify stationary phases, enhancing the separation of non-polar compounds. Additionally, it is employed in the treatment of nanoparticles and fillers to improve their compatibility with organic polymers, making it useful in the development of advanced composite materials. Its ability to form stable, long-lasting hydrophobic layers also makes it suitable for use in anti-corrosion coatings and protective treatments for electronic components.