The methylenetetrahydrofolate reductase (MTHFR) gene plays a major role in folate metabolism in infertile women. To date, limited studies have implicated the C677T polymorphism in MTHFR with female infertility, which is defined as the failure to accomplish clinical pregnancy with consistent unprotected sexual intercourse for 1 year; this disorder is influenced by various factors, including obesity and it affects in ~15% of couples during the reproductive period. However, limited molecular studies have been conducted pertaining to female infertility. The current study aimed to investigate the correlation between the C677T polymorphism in MTHFR and infertility in a Saudi population. In this study, 300 genomic DNA samples were extracted from 150 infertile and 150 fertile women, and genotyping was performed for the C677T polymorphism in MTHFR by using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The results revealed that the mutant T allele was significantly associated with infertility (odds ratio [OR] = 1.86; 95% CI = 1.15-2.99; p = 0.009). Additionally, the dominant and recessive modes of inheritance were positively associated with infertility, i.e., TT vs. CT+CC (OR = 2.98; 95% CI = 1.33-6.66; p = 0.005) and TT+CT vs. CC (OR = 1.89; 95% CI = 1.09-3.26; p = 0.02). The current results indicate that the T allele of the C677T polymorphism in MTHFR is a significant risk factor for infertility in women from a Saudi population.