The developed ultraviolet spectrophotometric method allows simple, eco- friendly, accurate and precise determination of anti-cancer agent alectinib hydrochloride in bulk and its pharmaceutical formulation. Alectinib hydrochloride standard drug was dissolved and quantitatively diluted in methanol to produced a solution of 8.0 µg/mL concentration and absorbance was measured at its detection wavelength 339 nm against methanol as reagent blank. The calibration curve obeyed Beer’s law in the concentration range of 2 - 12 µg/mL with correlation co-efficient of 0.9996. The detection limits and quantitation limits were found to be 0.57 µg/mL and 1.71 µg/mL, respectively which indicates method is sensitive. Precision experiment was for intra-day, inter-day and repeatability and %RSD was found to be within the specified limits. The percent recovery studies was performed at three different levels and was observed between 99.56 - 101.43 %, indicating insignificant interference from the other ingredients present in the capsule formulation. The robustness study was performed by deliberately variations in the method parameters and % RSD was calculated and found within the limits indicates that the method is robust. The method validation parameters such as accuracy, precision, linearity, detection limit and quantitation limit of were validated as per international council for harmonization guidelines Q2-R1 and successfully applied for the quantitative analysis of alectinib hydrochloride from its pharmaceutical formulation.