This study aimed to determine the chemical compositions and antioxidant and antimicrobial activities of thyme (Thymus vulgaris L.) and oregano (Origanum vulgare L.) cultivated in Egypt. The results conducted that the major constituents of the thyme essential oil were thymol (45.19%), p-cymene (13.59%), carvacrol (7.65%)and γ-terpinene (6.82%), while carvacrol (52.46%), terpine-4-ol (7.43%), terpineol,cis-beta (5.64%) and γ-terpinene (4.73%) were the major components of oregano essential oil by GC-MS analysis. The essential oils of thyme and oregano contained appreciable levels of total phenolic contents (228.78 and 129.43 mg PE/g) and showed good activity in DPPH radical scavenging with IC50 (68.95 and 96.47 mg/mL). Both extracts contained lower total phenolic contents (123.68 and 138.26 mg PE/g) than the essential oils but exhibited very strong DPPH radical scavenging capacity with IC50 (0.438 and 0.984 mg/mL, respectively). In addition, extracts and the essential oils proved great antimicrobial properties against human and plant pathogenic microorganisms. Klebsiella pneumonia was the most sensitive microorganism of oregano and thyme extracts (200μg/mL) with 35.8±0.89 and 37±0.47 mm inhibition zones, respectively. Thyme essential oil had the highest effect on Rhodotorula mucilaginosa with 25.7±0.27 mm, while oregano 16.5±0.24 mm on Aspergillus flavus.