Extracellular vesicles (EVs) serve as critical mediators of intercellular communication, facilitating drug resistance in tumor microenvironments by transferring bioactive components like proteins. Despite their potential role in non-small cell lung cancer (NSCLC), systematic investigations into exosome-mediated mechanisms underlying gefitinib resistance remain limited. In this study, we demonstrated that EVs contribute to enhanced drug tolerance, prompting a comprehensive proteomic analysis of both parental HCC827 cells and their exosomal counterparts. Proteomic profiling identified 4,098 exosome proteins, with 3,765 overlapping with cellular proteins. Fatty acid metabolism pathways were significantly enriched among proteins upregulated in resistant cells and EVs, with some enzymes showing pronounced correlations with resistance, particularly ACC1, whose expression levels were nearly eight times higher in resistant cells. Functional interventions demonstrated that either pharmacological inhibition of ACC1 with Firsocostat or siRNA-mediated ACC1 knockdown significantly reduced the gefitinib IC50 in HCC827/GR cells. This effect was associated with reduced ACC1 expression, alongside a partial restoration of fatty acid oxidation (FAO) activity in HCC827/GR cells and the reestablishment of their sensitivity to gefitinib-induced elevation of reactive oxygen species (ROS), ultimately reversing the drug-resistant phenotype.