There is continuously accruing evidence to suggest the health benefits of consuming fruits and vegetables. Food supplements may represent an effective and acceptable method to deliver a way of providing bioactive compounds to consumers. The aim of this work was to characterize the (poly)phenolic composition of three plant-based food supplements designed to integrate and increase the daily intake of dietary phenolics. The supplements are blends of berries, fruits, or vegetables made from a total of 36 different edible food plants. The best conditions for phenolic extraction were assessed and the total phenolic content of each supplement was estimated (it ranged from 50 to 176 mg/g powder). The analysis of the three supplements by uHPLC–MSn allowed to tentatively identify in all 119 (poly)phenolic compounds belonging to different classes, namely ellagitannins, gallotannins, dihydrochalcones, flavan-3-ols including proanthocyanidins, flavanones, flavones, flavonols, anthocyanins, hydroxybenzoic acids, hydroxycinnamic acids, phenylethanoids, and lignans. The contribution of these food supplements to the daily intake of (poly)phenolic compounds and, in turn, the potential contribution of such intake to health were discussed.