The determination of polyphenols in wines is of great interest in the field of food analysis due to health and organoleptic implications. In addition, the applicability of polyphenols as food descriptors to be used for characterization, classification, and authentication purposes is gaining popularity. In this work, a simple and reliable method based on HPLC separation in reversed-phase mode with UV-Vis detection was developed and applied to determine polyphenolic compounds in white wines. The chromatographic separation was performed using a C18 column under a methanol elution gradient and assessed by an experimental design approach. Analytical parameters were established under the optimal experimental conditions. LOD values were between 3 and 220 µg/L, and repeatability values were better than 1% for most of the analyzed polyphenols. Compositional data were further exploited to characterize white wines based on principal component analysis to discriminate among mono- and polyvarietal compositions.