SOX11 pioneer transcription factor is aberrantly expressed, it has an oncogenic role and its overexpression associates with worse prognosis in patients with mantle cell lymphomas (MCL). Using a proximity labeling (BioID2)/Mass Spectrometry-based proteomic strategyies, we identified SMARCA4, the central catalytic subunit of the SWI/SNF chromatin-remodeling complex, as one of the most significant SOX11-specific interacting proteins. SMARCA4 expression is directly regulated by SOX11, and its upregulation is associated with worse overall survival in patients with MCL, independently of other high-risk factors. Integration of global DNA-binding and transcriptomic profiles revealed that SOX11 and SMARCA4 share 60% specific peaks, predominantly in promoter regions. Disruption of SOX11:SMARCA4 interaction via SOX11 knockout or SMARCA4 PROTAC-degradation significantly reduced co-occupancy and co-targeted gene expression, including key BCR signaling pathway components. Our results suggest that SOX11:SMARCA4 complex binds to common regulatory sequences enabling the accession to chromatin and transcriptomic regulation of key oncogenic pathways for the development of MCL pathogenesis.