Mice are used universally as model organisms for studying heart physiology, and a plethora of genetically modified mouse models exist to study cardiac disease. Transcriptomic data for whole-heart tissue are available, but not yet for isolated ventricular cardiomyocytes. Our lab therefore collected comprehensive RNA-seq data from wildtype murine ventricular cardiomyocytes as well as from knockout models of the ion channel regulators CASK, dystrophin, and SAP97. We also elucidate ion channel expression from wild-type cells to help forward the debate about which ion channels are expressed in cardiomyocytes. Researchers studying the heart, and especially cardiac arrhythmias, may benefit from these cardiomyocyte-specific transcriptomic data to assess expression of genes of interest.