This research examined 30 olive oils commercially available in the United States for their fatty acid composition, oxidative stability, and antioxidant capacities. The olive oils in this study differed in their oxidative stability (23.64 - 212.1 h induction time) and concentrations of rancid byproducts (peroxide values: 40.46 - 65.07 umol t-butyl peroxide equivalents/g oil; p-anisidine values: 2.70 - 8.79 OD350/g oil; free fatty acid contents: 0.19 - 1.20 g oleic acid/100 g oil). These commercial olive oils also possessed varying concentrations of total phenolic contents (554 - 810 ug gallic acid equivalents/g oil) and oxygen radical absorbance capacities (1.4 - 11.7 umol Trolox equivalents/g oil) (P < 0.05). These data suggest that olive oils commercially available in the United States differ in their quality, stability, and nutritional value. Furthermore, the retail price may not reflect the quality, stability, and nutritional value of the olive oil.