In the present study, Origanum majorana L. essential oil (EO) was analyzed by gas chromatography-mass spectrometry (GC-MS) and evaluated for free radical scavenging and anticholinesterase activities. GC-MS analysis revealed the presence of 4-terpineol (29.97%), γ-terpinene (15.40%), trans-sabinene hydrate (10.93), α-terpinene (6.86%), 3-cycolohexene-1-1 methanal,a,a4-trimethyl-,(S)-(CAS) (6.54%), and sabinene (3.91%) as main constituents. Origanum majorana L. EO exhibited concentration-dependent inhibitory effects on 2,2'-diphenylpicrylhydrazyl (DPPH(•)), hydroxyl radical, hydrogen peroxide, reducing power, and lipid peroxidation with IC(50) values of 58.67, 67.11, 91.25, 78.67, and 68.75 µg/mL, respectively; while the IC(50) values for the standard trolox were noted to be 23.95, 44.97, 51.30, 42.22, and 52.72 µg/mL, respectively. Interestingly, cholinesterase inhibitory activity was also found with IC(50) values of 36.40 µg/mL. We can conclude that the marjoram EO has a significant potential to be used as a natural antioxidant and anti-AChE.