<p>Cardiovascular disease has been the leading cause of death worldwide for the past 30 years. Recent studies using single cell multiomics analysis have revealed that CD3⁺ T cells are among the most predominant cell types in diseased human cardiac and vascular tissues. Accumulating evidence has demonstrated the critical role of T cells in various cardiovascular diseases, including atherosclerosis, hypertension, myocardial infarction, neonatal heart injuries, autoimmune myocarditis, aortic aneurysm, and diabetic endothelial dysfunction. Recent research has also highlighted the therapeutic potential of CD4⁺ regulatory T (Treg) cells in promoting cardiovascular repair. In this review, we provide a systematic overview of how T cells regulate cardiovascular development, disease progression, and repair. We further discuss current and emerging therapeutic strategies, particularly those targeting Treg cells, aimed at reducing the incidence of cardiovascular events. Finally, we outline key areas for future investigation, including the identification of cardiovascular antigens that trigger T cell activation, the role of T cell aging in cardiovascular disease, and the molecular mechanisms underlying T cell function in the cardiovascular system. A deeper understanding of T cell biology could pave the way for novel, antigen-specific therapeutic interventions to prevent and treat cardiovascular diseases.</p>