Advances in circadian research revealed an intricate relationship between aging and circadian rhythms. However, whether and how the circadian machinery contribute to stem cell aging, especially in primates, remains poorly understood. In this study, we investigated the role of BMAL1, the only non-redundant circadian clock component, during aging in mesenchymal progenitor cells (MPCs). We observed an accelerated aging phenotype in both BMAL1 deficient human and cynomolgus monkey MPCs. Notably, this phenotype is mainly attributed to a transcriptional-independent role of BMAL1 in stabilizing the heterochromatin and thus preventing LINE1 activation. In senescent MPCs from human and cynomolgus monkeys, dampened LINE1 binding capacity of BMAL1 and synergistically activated LINE1 transcripts were observed. Furthermore, similar de-stabilized heterochromatin and aberrant LINE1s transcription was observed in the skin and muscle tissues from BMAL1-deficient cynomolgus monkey. Altogether, these findings uncover a noncanonical role of BMAL1 in stabilizing heterochromatin to inactivate LINE1 that drives aging in primates.