Abstract <p><b>Objective:</b> The study aims to investigate the flavonoid composition in enzymatic hydrolysates of lingonberry pomace (<i>Vaccinium vitis</i>-idaea) and aronia berry pomace (<i>Aronia melanocarpa</i>) to assess their potential as sources of flavonoids for food product formulations or dietary supplements. <b>Methods:</b> The enzymatic hydrolysis of lingonberry and aronia berry pomace was performed using a selected enzyme complex (pectinase, cellulase, protease, and lipase) under specific conditions. The flavonoid content in the hydrolysates was analyzed using high-performance liquid chromatography (HPLC) with diode array and mass spectrometric detection. The quantitative determination was carried out using the external standard method. The flavonoid composition was studied by comparing retention times, UV spectra, and mass spectra with standards and literature data. <b>Results and Discussion:</b> The study identified 10 flavonoids in the enzymatic hydrolysate of lingonberry pomace, with quercitrin being the most abundant (0.033%). The total flavonol content after enzymatic treatment increased by 16.8% compared to the control. In the aronia berry pomace hydrolysate, six flavonoids were identified, with hyperoside being the dominant flavonoid (0.029%). Enzymatic treatment of aronia berry pomace increased the flavonoid content by 46.6% compared to the control. The study highlights that both hydrolysates offer potential for the creation of preventive-purpose food products. <b>Conclusions:</b> Enzymatic treatment of berry pomace enhances the flavonoid content in the hydrolysates, which can be used in food products or dietary supplements. The results contribute to the development of food biotechnology by providing a sustainable way to utilize secondary berry raw materials and create biologically active food ingredients.</p>