•Fast and efficient discrimination method of different brands of whisky.•Correct classification of whisky brands by UV spectroscopy and PLS-DA.•Effective analysis of counterfeit samples with high correct classification rate.•Validation with samples belonging to known and unknown classes/brands. The discrimination of whisky brands and counterfeit identification were performed by UV–Vis spectroscopy combined with partial least squares for discriminant analysis (PLS-DA). In the proposed method all spectra were obtained with no sample preparation. The discrimination models were built with the employment of seven whisky brands: Red Label, Black Label, White Horse, Chivas Regal (12years), Ballantine’s Finest, Old Parr and Natu Nobilis. The method was validated with an independent test set of authentic samples belonging to the seven selected brands and another eleven brands not included in the training samples. Furthermore, seventy-three counterfeit samples were also used to validate the method. Results showed correct classification rates for genuine and false samples over 98.6% and 93.1%, respectively, indicating that the method can be helpful for the forensic analysis of whisky samples.