How steroid hormone receptors (SHRs) orchestrate transcriptional activity remains to be completely understood. Upon ligand activation, SHRs translocate to the nucleus and bind to the genome together with a co-regulator repertoire, crucial to induce gene expression. However, the essentiality of specific members of the SHR complex to drive transcription following hormonal stimuli remains elusive.  Through a FACS-based genome-wide CRISPR screen, we functionally dissected the co-regulatory complex of the Glucocorticoid Receptor (GR), and identified novel proteins that are imperative to drive ligand-induced transcription. We describe a novel functional interaction between PAXIP1 and STAG2 -Cohesin II subunit- as co-regulators of GR. We show that, without altering the GR cistrome, PAXIP1 and STAG2 depletion change the GR-transcriptome, by impairing the recruitment of 3D-genome organization proteins to the GR complex. Importantly, we show that PAXIP1 is required for stability of cohesin II on the genome, its localization to GR-bound sites, and maintenance of enhancer-promoter interactions. Moreover, in lung cancer, where GR acts a tumor suppressor, PAXIP1/STAG2 loss enhances GR-mediated tumor suppressor activity by modifying local chromatin interactions. All together, we introduce PAXIP1 and STAG2 as novel co-regulators of GR, required to maintain 3D genome architecture and ensure a correct transcriptional programme following hormonal stimuli.