A simple UV Spectrophotometric method for the quantitative estimation of Celecoxib using analytical grade methanol as solvent and acetyl chloride as the reagent for acetylation of Celecoxib has been developed. Acetyl derivative of Celecoxib obeys Beer’s law in concentration range 20-40 μg/ml at 270nm as absorption maximum. The recovery studies ascertained accuracy of purposed method and result validated according to ICH guidelines. The result of analysis has been validated statistically by recovery studies. This method was successfully carried out for the estimation of Celecoxib in capsule dosage form without the interference of common excipients.