The main objective of this study was to evaluate the antioxidant capacity of methanolic extracts from species of genus Phellinus: Ph. fastuosus, Ph. grenadensis, Ph. Merrillii, and Ph. Badius, in their respective polar fractions (aqueous) and nonpolar extracts (ethyl acetate), through tests of free-radical inactivation and hemolysis inhibition. The fungus species that gave the extract with the highest phenol content, total flavonoids, and antioxidant capacity [DPPH·, Trolox equivalents antioxidant capacity (TEAC), and hemolysis inhibition] was Ph. Merrillii, followed by Ph. fastuosus, Ph. Grenadensis, and Ph. Badius. The antioxidant capacities of the extracts, in descending order, were as follows: Ph. Merrillii (nonpolar), Ph. Fastuosus (nonpolar), Ph. Grenadensis (nonpolar), Ph. Fastuosus (polar), Ph. Merrillii (polar), Ph. Grenadensis (polar), Ph. Badius (nonpolar), and Ph. Badius (polar). Antioxidant capacity in the above Phellinus fungi species had EC50 values for DPPH inhibition of 0.45, 0.88, 1.31, 1.89, 2.14, 2.22, 3.42, and 6.00 mg/mL, respectively; TEAC values of 10400.29, 7635.53, 4855.05, 4415.39, 4041.68, 2989.2, 1937.7, and 842.42 µmol TE/g, respectively; and hemolysis inhibition values of 72.83, 66.95, 50.87, 50.28, 48.5, 42.82, 42.37, and 37.91%, respectively. In general, the fungus extract with the highest antioxidant capacity was the nonpolar fraction of Ph. Merrillii. The Phellinus species studied represent potential natural sources of bioactive compounds with antioxidant activity.