In the present work, phytochemical contents (total phenolic content, total flavonoids, and condensed tannins), antioxidant potentials, and antimicrobial activities of three plants in the Mediterranean genus Erodium (Erodium glaucophyllum, Erodium hirtum, and Erodium guttatum) from the Tunisia region were analyzed. The results showed that E. glaucophyllum contained high levels of polyphenols, flavonoids, and tannins. Therefore, E. glaucophyllum possesses high antioxidant activities (2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power scavenging activities), and high inhibition of linoleic acid oxidation. All three plants exhibited high antimicrobial activities. This study highlights tree plants’ importance as dietary sources for natural antioxidants can be used in traditional medicine and the pharmaceutical industry.