o-Chloronitrobenzene is primarily used as an intermediate in the synthesis of various chemicals, including dyes, pigments, and pharmaceuticals. It plays a key role in the production of agricultural chemicals, such as herbicides and insecticides, due to its reactivity and ability to form complex organic compounds. Additionally, it is utilized in the manufacture of rubber chemicals and as a precursor in the synthesis of other nitroaromatic compounds. Its applications extend to the research and development sector, where it is employed in organic synthesis and chemical studies.