The nucleolus is the membraneless organelle in the nucleus mainly responsible for ribosome biogenesis. It is also an excellent stress sensor and any changes on its architecture or composition leads to nucleolar stress deriving in cell cycle arrest and interruption of ribosomal activity. However, nucleolar stress sustained is also a contributing factor to pathologies like aging and cancer, highlighting the importance of its homeostasis in the cells. In this study, we identified and described the pivotal role of the RNA-binding protein Hnrnpk in the ribosome biogenesis and nucleolar dynamics. We developed an in vitro model of Hnrnpk overexpression with CRISPR-Cas9/SAM and an in vivo mouse model of Hnrnpk ubiquitous overexpression. We found that this overexpression disrupted translation and caused alterations in the nucleolar structure, resulting in nucleolar stress with alterations in the levels and localization of the nucleolar components fibrillarin and nucleolin, as well as impaired ribosome biogenesis. These aberrations trigger cell cycle arrest and cell senescence, and the phenotype could be rescued with haploinsufficiency of p53, suggesting that it is a consequence of a p53-dependant nucleolar stress mechanism. Finally, in our mouse model, Hnrnpk overexpression led to an aging phenotype with bone marrow failure and reduced lifespan, similar to a ribosomopathy-like phenotype. Together, our findings identify Hnrnpk as a novel master regulator of ribosome biogenesis and nucleolar homeostasis through p53, providing a new view of the orchestration of nucleolar integrity, ribosome function and cellular senescence.