Using a high-performance liquid chromatograph (HPLC), an analytical method for quantifying Vitamin D-3 was designed. The vitamin D-3 was separated using a C-18 column. As a mobile phase 97:3 ratio of methanol and water was used. The chromatogram of Vitamin D3 was identified at a wavelength of 264 nm at a flow rate of 1.2mL/min. The method was validated in accordance with the ICH Q2 (R1) guidelines. Several runs were carried out to determine the optimum dilution range. The devised approach was found to be linear with a r2 of 0.999 throughout a concentration range of 0.25-1.25µg/mL. At all levels, the mean percentage recovery of Vitamin D-3 were found to be between 95 and 105 percent, indicating that the approach was accurate. The percentage relative standard deviation was determined to be less than 2%, indicating that the approach was well-defined. For Vitamin D-3, the LOD and LOQ were determined to be 0.0001 and 0.0005, respectively. The approach was proven to be robust because there was no significant change in responses when the flow rate and mobile phase concentration were varied. The devised method passed all validation tests and may be used to quantify the amount of Vitamin D-3 in bulk as well as different pharmaceutical formulations KEYWORDS: Vitamin-D3, HPLC, LOD; LOQ, accuracy, precision, linearity