Recent studies have implicated KDM3A, which catalyzes removal of H3K9 methylation, is associated with tumorigenesis. However, the biological role of KDM3A in multiple myeloma, has not been delineated. Here we identify KDM3A-KLF2-IRF4 axis dependence in multiple myeloma. We demonstrate that knockdown of KDM3A leads to apoptosis and significant growth inhibition in myeloma cells. Mechanistically, KDM3A directly regulates myeloma cell survival factor IRF4 expression through H3K9 demethylation at its promoter. We further show that KDM3A directly regulates KLF2 expression and that knockdown of KLF2 leads to growth inhibition in myeloma cells.