Background/Objectives: Emerging evidence suggests that patients suffering from COVID-19 may experience neurocognitive symptoms. Furthermore, other studies indicate a probable association between leukocyte telomere length (LTL) and neurocognitive changes in subjects with post-COVID-19 condition. Our study was designed to determine the correlation between telomere length and cognitive changes in post-COVID-19 subjects. Methods: This study included 256 subjects, categorized based on SARS-CoV-2 infection from 2020 to 2023. In addition, subjects with a psychiatric diagnosis were considered. Moreover, the MoCA and MMSE scales were applied. Telomere length was determined using a polymerase chain reaction, and statistical analysis was employed using ANOVA and X2 tests. Results: We identified a decrease in LTL in individuals with post-COVID-19 conditions compared to those without SARS-CoV-2 infection (p ≤ 0.05). However, no association was found between LTL and cognitive impairment in the subjects post-COVID-19. Conclusions: The findings suggest that LTL is affected by SARS-CoV-2 infection. Nonetheless, this important finding requires further research by monitoring neurological changes in subjects with post-COVID condition.