<p>Proteasome inhibitors are currently at the forefront of multiple myeloma (MM) treatment. Drug resistance in MM challenges treatment, causing relapses and making the disease incurable. Urgent strategies are needed to combat resistance and understand its mechanisms. Targeting the metabolism of MM is a promising approach, as metabolic changes are associated with the disease and its adaptation to therapy. Metabolomics, the study of small molecule metabolites, is a powerful tool for identifying and analyzing a cell’s metabolic phenotype. In this study, we aimed to investigate alterations in the metabolome of carfilzomib-resistant MM cells. We conducted global metabolomic comparative analyses of two carfilzomib-sensitive MM lines with their carfilzomib-resistant progenies. Additionally, we performed bioinformatic analysis to determine the top canonical pathways, biological functions, and upstream regulators linked to the differences in metabolomic profiles. Differential metabolite analysis showed increased amino acid and decreased fatty acid concentrations in carfilzomib-resistant cells. Functional analysis revealed increased glucose-6-phosphate oxidation and inhibited lipid accumulation in resistant lines. The bioinformatic analysis predicted PML, ARNT D-glucose, and UPC1 as upstream regulators of observed changes in carfilzomib-resistant cells. This study presents one of the first metabolomic profiles of two carfilzomib-resistant MM lines and the metabolome changes that may contribute to carfilzomib resistance.</p>