Throughout the world, people’s diet is generally quite restricted regarding the variety of plants used in their daily regime. The Unconventional Food Plant (UFP) Lactuca canadensis L. is an edible species of wild lettuce sparsely described in literature and considered to be native from the eastern and central parts of North America. To valorize this species as potential alternative food, an analysis of its nutritional, chemical, and bioactive properties was performed. The results specify the occurrence of organic acids, mainly quinic acid (127.9 ± 0.6 g/kg dry weight (dw)), polyunsaturated fatty acids (65.3%), among which are linolenic acid (44.4 ± 0.4 %), and tocopherols, mostly α-tocopherol (61.2 ± 0.7 mg/kg dw). Additionally, eight phenolic compounds were also identified, among which luteolin-O-glucuronide was found in larger amounts in both infusion and hydroethanolic extracts (5.46 ± 0.09 and 4.6 ± 0.1 mg/g dw, respectively). Carbohydrates and proteins were the main macronutrients (603 ± 1 and 177.5 ± 0.3 g/kg dw, respectively), followed by ashes (166.5 ± 0.9), indicative of a great amount of minerals. Additionally, good antioxidant and antibacterial activities were detected in the analyzed extracts. In general, our results contribute to extend the range of different, unexploited, and nutritionally balanced plant foods, such as Lactuca canadensis, that can and should be included in the daily diet.