(S)-(-)-2-Phenylbutyric acid is primarily utilized in the pharmaceutical industry as a key intermediate in the synthesis of various active pharmaceutical ingredients (APIs). Its chiral structure makes it valuable in the production of enantiomerically pure compounds, which are essential for developing drugs with specific therapeutic effects.

In addition to pharmaceuticals, it finds application in organic synthesis, where it serves as a building block for creating complex molecules. Its phenyl group and carboxylic acid functionality allow it to participate in a range of chemical reactions, including esterification, amidation, and coupling reactions.

Furthermore, it is used in research and development for studying stereochemistry and designing new chemical entities with potential biological activity. Its role in asymmetric synthesis is particularly noteworthy, as it aids in the production of compounds with high enantiomeric purity, which is crucial in many therapeutic applications.