Spin coating technique has been widely used in the fabrication of thin films due to its ease of use, inexpensive processing cost and providing control over the thickness of the film. Various polymers have been used in fabricating spin-coated thin film and poly(3-hexylthiophene) (P3HT) is one of the prevalent polymers utilized due to its semiconducting properties and flexibility in processing. In this study, P3HT is deposited on pre-cleaned quartz glass by the method of spin coating. The spin coating speed is varied from 500, 1000, 1500, 2000, 2500 rpm and the optical properties of the films are characterized by using a UV-Vis spectrophotometer. The UV-Vis absorption spectra of P3HT designated absorption peaks in the range of 520 nm to 550 nm. It is shown that the absorbance of P3HT is decreased with every increment of the spinning speed. Thus revealing the dependency of P3HT thin films’ optical properties on spin coating speed.