Objective <p>Transcranial direct current stimulation (tDCS) is a safe, non-invasive neuromodulation method that delivers a low-intensity, constant direct current through electrodes positioned on the scalp. Therefore, the purpose of this systematic review is to examine the effects of tDCS on psychological factors in athletes.</p> Methods <p>Primary sources were sourced from four databases: SCOPUS, PubMed, CENTRAL, and Web of Science. The search period spanned from the inception of these databases up to February 1, 2026. Hedges’ g effect size, and 95% confidence intervals (CIs) were computed using either random or fixed-effect models for the outcomes.</p> Results <p>After the screening process, a total of 14 studies comprising 376 participants were included in the systematic review. The results of the meta-analysis showed that tDCS improved attentional performance (1.18 [95% CI: 0.59 to 1.78], <i>p</i> = 0.001), cognitive function (1.12 [95% CI: 0.81 to 1.42], <i>p</i> = 0.001), and reduces mental fatigue (-1.35 [95% CI: -0.84 to -1.85], <i>p</i> = 0.001), reaction time (-1.35 [95% CI: -1.04 to -1.66], <i>p</i> = 0.001).</p> Conclusion <p>The present meta-analysis demonstrates that the tDCS notably enhances attention, cognitive skills, and reduces mental fatigue, and reaction times among athletes. This research offers a detailed examination of how tDCS influences psychological aspects specifically in athletes, highlighting its potential as a valuable method for enhancing psychological performance in sports.</p> Trial registration <p>CRD420261304015</p>