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This study was designed to evaluate the antioxidant activity of the phenolic compounds of 4 plants from the Lamiaceae family (Salvia officinalis, Satureja calamintha, Mentha pulegium, and Marubium vulgare) using the ferric reducing antioxidant power (FRAP) assay and the radical scavenging method (DPPH). Preliminary phytochemical screening showed that the major constituents of the 4 plants’ crude extracts (hydromethanolic and hydroacetonic) were tannins, saponins, quinones, flavonoids, terpenoids, and reducing compounds. Through quantitative analysis, varying levels of polyphenol, flavonoids, and condensed tannins were recorded. The highest polyphenol content was found in the crude aqueous/methanol extract of Salvia officinalis(188.92 ± 1.19 mg GAE/gE), followed by the crude aqueous/acetone extract of Mentha pulegium(176.55 ± 2.49 mg GAE/gE). With regard to flavonoid and condensed tannins content, the highest levels were found in the aqueous/methanol extract of Mentha pulegium and the aqueous/acetone extract of Satureja calamintha(93.64 ± 0.26 mg QE/gE, and 25.44 ± 0.71 mg QE/gE), respectively. The scavenging activity of the DPPH free radical revealed that the aqueous/methanol extract of Salvia officinalis exhibited a relatively high antioxidant activity (IC50 = 1.07 μg/ml) compared with ascorbic acid (IC50 = 0.91 μg/ml). The FRAP assay revealed that the extracts of Mentha pulegium exhibited the greatest iron-reducing power (EC50 = 0.147 mg/ml), but its power was still lower than that of ascorbic acid (EC50 = 0.057 mg/ml).