Antioxidant capacity and the radical-scavenging activity are the biological basis for the health benefits attributed to olive oil and olive leaves. Excess reactive oxygen species (ROS) have been linked to the risk of developing diseases such as cancer, rheumatoid arthritis, neurodegenerative disease, and other chronic conditions. To further determine the antioxidant capacity of olive oil compounds, an in vitro study tested the overall properties of oleuropein and hydroxytyrosol. In this experimental study, both compounds were capable of suppressing DNA oxidative stress damage. Furthermore, when in vitro cells were pretreated with either compound, primary DNA damage was prevented. After comparing both compounds, hydroxytyrosol revealed better anti-oxidant performance. As demonstrated by this study, olive oil has numerous health properties, but in particular it fulfills the body’s need for antioxidant nutrients.