Exogenous glucocorticoids are frequently used to treat inflammatory disorders and as adjuncts in solid cancers. However, their use is associated with severe side effects and therapy resistance. Novel glucocorticoid receptor (GR) ligands with a patient-validated reduced side effect profile have not yet reached the clinic. GR is a member of the nuclear receptor family of transcription factors and heavily relies on interactions with coregulator proteins for its transcriptional activity. To elucidate the role of the GR interactome in the altered transcriptional activity of GR following treatment with agonists, antagonists or lead selective GR agonists and modulators (SEGRAMs), we generated comprehensive interactome maps by high-confidence proximity proteomics in lung epithelial carcinoma cells. We found that the GR antagonist RU486 and the SEGRAM Dagrocorat both reduced GR interaction with CREB-binding protein (CBP)/p300 and the mediator complex compared to the full agonist Dexamethasone. Our data offer new insights into the role differential coregulator protein recruitment in shaping specific GR-mediated transcriptional responses.