3-Octylpyridine is primarily used as a solvent and extractant in various chemical processes. It is particularly effective in the extraction of metal ions, such as uranium and rare earth elements, from aqueous solutions. Its unique structure allows it to form stable complexes with these metals, making it valuable in nuclear fuel processing and recycling industries. Additionally, it serves as an intermediate in the synthesis of specialty chemicals, including surfactants and corrosion inhibitors. Its application extends to research fields, where it is utilized in studies involving ionic liquids and phase transfer catalysis.