<p>Steroids are known to have proarrhythmogenic properties, even though they have been demonstrated to lower the incidence of atrial fibrillation following heart surgery. According to the American Heart Association (AHA), this negative impact was still inconsistent. Therefore, this study aims to elucidate the association between corticosteroid usage and atrial fibrillation.This systematic review employed the keywords “corticosteroids” and “atrial fibrillation,” collected from PubMed, Scopus, Web of Science, and Google Scholar. Meta-analysis was performed using a random effects model through Mantel-Haenszel analysis. Disproportionality analysis and Bayesian analysis were conducted utilizing the United States Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) datasets. A narrative review was conducted to obtain mechanistic insights into corticosteroid-induced atrial fibrillation. The meta-analysis of 23 studies involving 679,330 individuals indicated that exogenous steroids elevated the risk of atrial fibrillation by 1.74 times (95% CI = 1.55 to 1.96, <i>p</i> &lt; 0.0001). Intravenous, oral, and inhaled corticosteroids elevated the risk of atrial fibrillation by 2.02, 1.95, and 1.67 times, respectively. The risk of atrial fibrillation was elevated with the administration of corticosteroids at higher doses and for longer durations. Disproportionality analysis from FAERS indicated that some corticosteroids exhibited a significant reported odds ratio (ROR). Corticosteroids can induce mechanical and electrical remodeling of cardiomyocytes, as well as cardiomyocyte senescence, cardiac hypertrophy, hypertension, and diabetes mellitus, all of which may collectively increase susceptibility to atrial fibrillation. Corticosteroids might increase the risk of atrial fibrillation in a dose- and duration-dependent fashion. Inflammation should be regarded as a confounding factor in this conclusion.</p>