1-Ethynylnaphthalene is primarily utilized in organic synthesis and materials science. It serves as a key building block in the development of conjugated polymers and organic semiconductors, which are essential for creating flexible electronics, light-emitting diodes (LEDs), and photovoltaic devices. Its structure allows for efficient π-conjugation, enhancing the electronic properties of the materials. Additionally, it is employed in the synthesis of complex organic molecules for pharmaceutical research, particularly in the development of novel drug candidates. Its reactivity as an alkyne also makes it valuable in click chemistry reactions, enabling the formation of stable and functionalized compounds.