3-Chloro-4-ethynylbenzoic acid is primarily used in organic synthesis as a building block for more complex chemical structures. Its ethynyl group makes it a valuable intermediate in click chemistry reactions, particularly in the formation of triazoles. This compound is also utilized in the development of pharmaceutical agents, where its benzoic acid moiety can be modified to create potential drug candidates. Additionally, it serves as a precursor in the synthesis of materials for organic electronics, contributing to the creation of conductive polymers and other advanced materials.