The current study explores a design and development of the simple, fast, green and selective novel method of UPLC to quantify pitavastatin and ezetimibe simultaneously. The combined approach of Green Analytical Method with Quality by Design-based risk assessment was done using the Ishikawa fishbone diagram followed by a rotatable central composite design used for the optimization. The optimal chromatographic separation was attained through a mobile phase of 72: 28% v/v ethanol and 0.1% orthophosphoric acid (pH 3.5), with a 0.31 mL min−1 flow rate. The developed UPLC-PDA method was sensitive and specific for pitavastatin and ezetimibe, with linearity ranging from 2 to 30, 10–150 μg mL−1 with an R2 of 0.9999 and 0.9997, respectively. The forced degradation study of stability-indicating assay results shows the degradation in respective stress conditions. The developed UPLC method was validated and found to have sensible results with good linearity, accuracy and precision. Further, the greenness was evaluated using five states of art metrics like NEMI, GAPI, AES, AMGS, and AGREE metrics and found the greenest results. Based on the results we concluded that the developed UPLC method could be efficient for the simultaneous determination of pitavastatin and ezetimibe in bulk and tablet dosage.