Salinity is detrimental to abiotic stress occurs in arid and semi-arid environmental conditions. The salinity adversely affects the growth, yield, and quality of plants. Some plants are sensitive to salt stress while others are resistant to the tolerance mechanisms induced by physiological, biochemical, and molecular responses. The present study was conducted to investigate the effectiveness of mycorrhizal colonization (Glomus clarum) and silicon (Si) under different salinity levels on antioxidant enzymes activity (super oxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione oxidase (GPX) and lipid peroxidation (MDA)) of two salinity sensitive (cv. Demre) and tolerant (cv. Karaisali) pepper cultivars. Three different salt doses (0 mM NaCl, 75 mM NaCl, 150 mM NaCl), with AM and 2 mM K₂SiO₃ were applied in the 4-L vermiculite-containing pots. The antioxidant enzyme activities were increased with increasing salt doses. In all antioxidant enzymes, it was observed that the enzyme activities showed differences in pepper genotypes with different salt sensitivity. Catalase, ascorbate peroxidase, and glutathione reductase activities were higher in the salt-sensitive pepper genotype. Si and mycorrhiza treatment improved the defense mechanisms in peppers and attenuated the oxidative damage in cellular functional molecules caused by the overproduction of reactive oxygen species (ROS) under salt stress. Therefore, due to increased salt tolerance, mycorrhiza and silicon applications can be used in areas with salinity problems.