Ionizing radiation, extensively used in medical diagnostics and therapy, and other industrial uses, is of major concern to biological systems because it causes damage at the molecular and cellular level. Of the non-cancerous effects, radiation-induced cardiovascular diseases (RICVDs) are gaining more prominence due to their clinical implications. This scoping review analyzes the relationship between ionizing radiation exposure and circulatory system diseases, with special focus on cardiovascular hazards among radiotherapy-exposed, occupational, or accident-exposed populations. Through systematic searching of PubMed (2020–2024) and Google Scholar (2010–2024), 30 studies were found meeting the criteria. Results indicate a definite dose-response and age-related correlation of radiation exposure with cardiovascular pathology. Low doses (<1 Gy) are linked with endothelial dysfunction and oxidative stress, whereas moderate (1–5 Gy) and high doses (>5 Gy) are linked with myocardial fibrosis, arterial injury, and conduction disturbances. The major cardiovascular outcomes recognized are coronary artery disease, cardiomyopathy, valvular heart disease, and stroke—diseases induced by radiation-induced inflammation, fibrosis, and vascular remodelling. Age-related patterns emphasize that, although older persons are more likely to have clinically severe manifestations, young patients might have subclinical injuries with lasting consequences. The review supports findings from atomic bomb survivor cohorts and cancer patients showing a linear dose-response even for heart doses of 0.5 Gy. In spite of the radiation protection recommendations set by international regulatory agencies like ICRP, UNSCEAR, and NCRP, gaps remain large to evaluate risks in chronic low-dose exposure. New imaging techniques, radiotherapy, and individualized dosimetry provide encouraging directions for reducing risks. Longitudinal studies, age-modified risk models, and interdisciplinarity especially in cardio-oncology remain imperative to enhance preventive strategies and patient care.