4-Ethyl-3-fluorophenylboronic acid is primarily used in organic synthesis, particularly in Suzuki-Miyaura cross-coupling reactions. This reaction is widely employed in the pharmaceutical industry to create complex organic molecules, including drug candidates. The compound serves as a key building block for introducing the 4-ethyl-3-fluorophenyl group into target molecules, which can enhance their biological activity or modify their physical properties. Additionally, it is utilized in materials science for the development of organic electronic materials, where the incorporation of specific aryl groups can influence the material's conductivity or optical properties. Its stability and reactivity make it a valuable reagent in both academic research and industrial applications.