Tetrakis(decyl)ammonium bromide is widely used as a phase transfer catalyst in organic synthesis. It facilitates the transfer of reactants between immiscible phases, enhancing reaction rates and yields in processes such as nucleophilic substitutions, oxidations, and reductions.

In material science, it serves as a surfactant or stabilizer in the preparation of nanoparticles and polymers, ensuring uniform dispersion and controlled particle size.

Additionally, it is employed in the formulation of biocides and disinfectants, where its antimicrobial properties help in controlling microbial growth in various industrial and water treatment applications.

Its amphiphilic nature also makes it useful in the study of membrane mimetics and in the development of drug delivery systems, where it aids in improving solubility and bioavailability of active pharmaceutical ingredients.