The evolutionarily conserved Par3/Par6/aPKC complex regulates the polarity establishment of diverse cell types. This study shows that the Par complex exhibits cell cycle-dependent condensation in *Drosophila* neuroblasts, driven by liquid-liquid phase separation (LLPS). Par3's open conformation undergoes autonomous phase separation due to NTD-mediated oligomerization. Par6 enhances Par3 phase separation, and aPKC is concentrated in the condensates but can disperse them upon activation via Par3 phosphorylation. Perturbations of Par3/Par6 phase separation impair apical-basal polarity and lineage development, suggesting LLPS as a common mechanism for cortical condensation of cell polarity complexes.
