Membraneless organelles enable the formation of micro-compartments within the cell but the functions of these dynamic organelles remain poorly understood. A prominent example of the dynamic nature of these compartments is during the cell cycle when many membraneless organelles dissolve during mitosis and reform in G1. To investigate this we undertook at CRISPR-screen to knockout a range of membraneless organelles and assess the impact of cell cycle progressing using the cell cycle optical sensor FUCCI(CA). This screen revealed a role for the cytosolic Processing bodies (P-bodies) in cell cycle regulation. P-bodies control the speed of M-G1 transition by controlling the mRNA stability of key cell cycle regulators. Our work supports the role of membraneless organelles as key regulators of cell function and reveals a novel layer of cell cycle control.