Background: The EGF domain-specific O-GlcNAc transferase (EOGT), a migrasome marker, plays emerging roles in cancer biology through O-GlcNAcylation modifications, yet its pan-cancer functions and therapeutic implications remain underexplored. This study aimed to systematically characterize EOGT’s oncogenic mechanisms across malignancies, with particular focus on hepatocellular carcinoma (HCC) progression and sorafenib resistance. Methods: Multi-omics analysis integrated TCGA/GTEx data from 33 cancer types with spatial/single-cell transcriptomics and 10 HCC cohorts. Functional validation employed Huh7 cell models with EOGT modulation, RNA sequencing, and ceRNA network construction. Drug sensitivity analysis leveraged GDSC/CTRP/PRISM databases, while immune microenvironment assessment utilized ESTIMATE/TIMER algorithms. Results: EOGT showed cancer-specific dysregulation, marked by significant upregulation in HCC correlating with advanced stages and poor survival. Pan-cancer analysis revealed EOGT’s association with genomic instability, tumor stemness, and angiogenesis. Experimental validation demonstrated EOGT’s promotion of HCC proliferation and migration. A novel exosomal circ_0058189/miR-130a-3p/EOGT axis was identified, showing that circ_0058189 was upregulated in HCC tissues, plasma samples and exosomes of sorafenib-resistant cells. Conclusion: This study establishes EOGT as a pan-cancer angiogenesis biomarker, while elucidating its role in therapeutic resistance via exosomal circRNA-mediated regulation, providing mechanistic insights for targeted intervention strategies.