4-Ethylphenylboronic acid is widely used in organic synthesis, particularly in Suzuki-Miyaura cross-coupling reactions. This reaction is essential for forming carbon-carbon bonds, making it valuable in the production of pharmaceuticals, agrochemicals, and advanced materials. The compound serves as a key intermediate in the synthesis of complex organic molecules, including drug candidates and biologically active compounds. Additionally, it is employed in the development of sensors and catalysts due to its ability to interact with various functional groups. Its role in these applications highlights its importance in modern chemical research and industrial processes.