<p>Aging is a major contributor to functional decline of the heart and various cardiovascular diseases. Alterations across different cardiac cell types must be tightly orchestrated during the normative aging process that has begun to be mapped at the transcriptional level through single-cell RNA-sequencing. However, current rodent models are limited in their capacity to experimentally test large numbers of candidate differentially expressed genes (DEGs). As an attractive alternative, the African Turquoise Killifish (ATK) promises more efficient genetic studies of cardiac aging because it has the shortest lifespan among vertebrates. Despite its experimental advantages, single-cell transcriptomic studies on cardiac aging in ATK have not yet been conducted. Here, we generated scRNA-seq profiles of hearts from young and old GRZ strain ATK and demonstrated changes in cellular composition, gene expression, functional pathways, and intercellular communication during cardiac aging. This dataset not only recapitulates previously characterized cardiac aging hallmarks but also highlights the contribution of underappreciated cardiovascular cell types, such as epicardium and immune cell types, to cardiac aging.</p>