Currently, no chiral analytical method exists for quantifying the enantiomer of Etrasimod. A swift, accurate, andvalid normal-phase HPLC method was designed and validated in accordance with ICH criteria to quantifytheenantiomer in both the API and drug product. Various polysaccharide chiral columns were screened under reverse- phase, polar-organic, and normal-phase circumstances. The most effective enantiomeric separation was achievedusing the YMC CHIRAL ART Cellulose SJ column (25 × 0.46 cm, 5 µm), offering excellent resolution. Anisocratic mode was carried out using a mobile phase containing n-hexane, methanol, ethanol, and TFA(85:10:05:0.1% v/v/v/v), with column oven temperature of 95°F, 1.0 mL/min mobile phase flow rate, and the UVdetector was set at 280 nm. The method showed linearity between 0.5 and 1.875 µg/mL (r² > 0.999), with a limit of quantification and detection of 0.5µg/mL and 0.25 µg/mL, respectively. Recovery ranged from89%to 108%, confirming the method's precision, accuracy, and suitability for routine enantiomer quantification in quality control.