Wild garlic (Allium ursinum L.) is one of the species widely distributed in Europe and Asia and is often nutritionally neglected, characterized by a high content of various phytochemicals with high therapeutic potential and a range of biological activities. The aim of this study was to determine the content of bioactive compounds in the leaves of wild garlic populations collected from different micro-locations, and to determine the differences in the content of phytochemicals in the vegetative and generative phases. A significant content of different specialized metabolites was detected in all analyzed leaves of wild garlic populations regardless of the different factors (location and phenophase): vitamin C content with the highest determined value of 63.31 mg/100 g fw; total phenolic content with the highest determined value of 186.18 mg GAE/100 g fw (according to gallic acid in fresh sample); and antioxidant capacity with the highest determined value of 2230.66 µmol TE/L (according to Trolox). Significant differences in all the phytochemicals analyzed were observed depending on both the location and phenophase of the plants, with the most pronounced differences depending on the phenophase. Thus, lower levels of polyphenolic compounds and vitamin C were generally observed before the flowering phase, while the trend toward higher levels of pigment compounds was observed during the flowering phase of the plants. The results suggest that the leaves of wild garlic can be considered a valuable source of a variety of specialized metabolites with high antioxidant capacity, and thus have high production potential for various functional products and food supplements of natural origin, which are important for the promotion of human health.