The edible mushroom Schizophyllum commune is traditionally consumed in the Democratic Republic of the Congo, but its nutritional properties remain poorly documented. This study evaluated the nutritional composition, mineral profile, and antioxidant potential of S. commune samples from the cities of Kikwit and Mbandaka. Proximate (AOAC methods), mineral (by ICP-OES), and phytochemical analyses were performed on lyophilized samples, with statistical analyses including ANOVA and Student's t-test (p < 0.05). The results showed that protein (28.28–35.2 g/100 g DM), carbohydrate (29.98–30.56 g), and fiber (20.5–23.9 g) contents differed significantly between the two sites. Potassium (1195–1420 mg/100 g) and phosphorus (560.9–605.9 mg) dominated the mineral profile, while polyphenols (69.2–73.2 mg GAE/g) and tannins (66.1–76 mg CE/g) were the main antioxidant compounds. In conclusion, S. commune exhibits a balanced nutritional profile and notable levels of bioactive compounds, supporting its promising use as a functional food.