The world's arid and semi-arid regions are frequently subjected to significant abiotic stresses, particularly salt stress, which threaten crop yield and production. In light of this, the current study aimed to assess the mitigating effects of salinity stress through different doses of L-methionine (0, 50, and 100 mg L-1), with the goal of promoting sustainable production of Dekalb maize hybrids (Dk-6317 and Dk-9108). The experiment was carried out during spring 2020 in a pot setup, where salt stress was induced by applying two levels of sodium chloride (0 and 120 mM). Exogenous L-methionine at 50 mg L-1 and 100 mg L-1 significantly improved maize growth, yield, photosynthetic pigments, and antioxidant defence characteristics. Salt stress significantly (p ≤0.05) reduced plant height (17.89% and 21.40%), shoot fresh weight (17.13% and 17.42%), shoot dry weight (18.03% and 29.98%), root fresh weight (21.56% and 31.02%), root dry weight (33.37% and 30.51%), and leaf area (16.28% and 21.18%) of Dk-6317 and DK-9108, respectively, when compared to L-methionine treatments. Furthermore, correlation analysis revealed a significant (p ≤0.05) correlation between various studied traits, including enzymatic and stress-related antioxidants, as well as yield attributes. As a result, antioxidant enzyme activity such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) promotes plant growth by positively correlating with photosynthetic pigments, resulting in higher yield attributes. It appears that L-methionine improves maize crop development when subjected to salt exposure, a novel aspect of L-methionine's beneficial role. A beneficial interaction between L-methionine and photosynthetic pigments suggests its potential to mitigate salt toxicity effects and enhance sustainable maize production.