Circular RNAs (circRNAs) are non-coding RNA molecules with a circular structure, primarily generated from linear precursor mRNAs through a back-splicing mechanism. circRNAs regulate various pathophysiological processes, including the proliferation, migration, differentiation, senescence, and apoptosis of cardiomyocytes, thereby playing a crucial role in cardiovascular diseases such as atrial fibrillation, atherosclerosis, myocardial infarction, heart failure, dilated cardiomyopathy, and hypertrophic cardiomyopathy. With the increasing variety of cancer treatments, the incidence of treatment-induced cardiotoxicity has also escalated. Recent studies have revealed a significant association between circRNAs and Cancer therapy-induced cardiotoxicity (CTIC). This review summarizes the biological functions of circRNAs, providing an overview of the mechanisms through which various circRNAs influence CTIC. Furthermore, we explore the potential cardiovascular implications of targeting specific circRNAs as diagnostic and therapeutic approaches for immune checkpoint inhibitor (ICI) resistance, positioning circRNAs as promising diagnostic and therapeutic targets for CTIC.