Fruits from forty-two blueberry cultivars, including thirty-six rabbiteye (Vaccinium ashei Reade), three V. ashei hybrid derivatives and three northern highbush (V. corymbosum L.) standards, were evaluated for their antioxidant activities against peroxyl free radicals (ROO·), hydroxyl radicals (OH·), hydrogen peroxide (H2O2), superoxide radicals (Symbol) and singlet oxygen (1O2) radicals. The differences in scavenging capacities for these radicals among forty-two selected blueberry cultivars were significant. Oxygen radical absorbance capacity values ranged from 33.8 to 118.7 μmol Trolox equivalents (TE) g fresh wt−1, 196.1 to 518.8 μmol TE g dry wt−1 and 7.1 to 22.2 μmol cm−2-surface area. Extracts from fruit of pure rabbiteye had higher levels of scavenging capacities of oxygen species Symbol, 1O2 and H2O2 compared to V. ashei hybrid derivatives and northern highbush blueberry standards. The rabbiteye cultivars ‘Early May’ and ‘Centurion’ had the highest scavenging capacity for the reactive oxygen species, not only for ROO· and ·OH, but also for Symbol, 1O2 and a strong oxidant, H2O2. In contrast, ‘Pink Lemonade’ (pink-fruited) had the lowest ability to inhibit free radical activity of ROO·,·OH, 1O2, and H2O2.‘Snowflake’ had the lowest scavenging capacity for Symbol. Blueberry cultivars with high antioxidant activity and radical scavenging capacity have potential to improve human health and can possibly be used as parents for future blueberry breeding programs to develop new blueberry cultivars with higher antioxidant activity.