Circadian regulation of the cell cycle progression generates a diurnal supply of newborn cells to replace those lost in organs and tissues. In this study, we analyzed circadian time-dependent changes in cell types within the mouse tongue epithelium. Using single-cell RNA sequencing, we observed circadian time-dependent changes in the populations of stem/progenitor cells and the differentiated cells in mice tongues. Notably, we observed time-dependent changes in the type II taste cell population, which were abolished by ablation of taste bud stem cells, thereby inhibiting cell proliferation within the taste cell population. Through experiments with taste bud organoids (TBOs), we found a 24-h cell cycle period, which was disrupted by the knockdown of the core-clock gene