Chia (Salvia hispanica L.) is a plant classified as a member of the Lamiaceae family. From a nutritional perspective, it is a considerable source of carbohydrates, proteins, fats, and dietary fiber with a very high number of antioxidants. The aim of this work is to evaluate the antioxidant activity of the alcoholic extract of chia seeds (Salvia hispanica L.) using multiple assays, including linoleic acid peroxidation inhibition, hydrogen peroxide scavenging, reducing power, and ferrous ion chelation, and to compare these activities against the synthetic antioxidant butylated hydroxytoluene (BHT) and the natural antioxidant tocopherol. Chia seeds were collected from local markets. After alcoholic extraction, the chia extract was evaluated using several tests including glycosides test, Keller-Kiliani test, sodium hydroxide test, alkaloids test, phenolic compounds test, tannins test, resins test, and flavonoids test. It also involved the measurement of antioxidant activity using the linoleic acid system, reducing power, scavenging of hydrogen peroxide, and ferrous ion binding activity. The results showed that the alcoholic chia extract demonstrated significantly higher antioxidant activity (p < 0.05) than the natural antioxidant tocopherol at 100% concentration. The alcoholic extract also showed the ability to scavenge hydrogen peroxide at 86.7% at 100% concentration, which was statistically superior to BHT (84.70%, p = 0.031). Our study demonstrated satisfying antioxidant activity of the alcoholic chia plant extract compared to the synthetic antioxidant BHT and tocopherol. In addition, the alcoholic extract of the chia plant showed significant ability to scavenge hydrogen peroxide, superior to BHT.