Basal nuclear factor κB (NF-κB) activation is required for hematopoietic stem cell (HSC) homeostasis in the absence of inflammation; however, the upstream mediators of basal NF-κB signaling are less well understood. Here, we describe TRAF6 as an essential regulator of HSC homeostasis through basal activation of NF-κB. Hematopoietic-specific deletion of Traf6 resulted in impaired HSC self-renewal and fitness. Gene expression, RNA splicing, and molecular analyses of Traf6-deficient hematopoietic stem/progenitor cells (HSPCs) revealed changes in adaptive immune signaling, innate immune signaling, and NF-κB signaling, indicating that signaling via TRAF6 in the absence of cytokine stimulation and/or infection is required for HSC function. In addition, we established that loss of IκB kinase beta (IKKβ)-mediated NF-κB activation is responsible for the major hematopoietic defects observed in Traf6-deficient HSPC as deletion of IKKβ similarly resulted in impaired HSC self-renewal and fitness. Taken together, TRAF6 is required for HSC homeostasis by maintaining a minimal threshold level of IKKβ/NF-κB signaling. Display omitted •TRAF6 is required for hematopoietic stem cell (HSC) homeostasis•TRAF6 regulates HSC quiescence, self-renewal, and differentiation•Deletion of TRAF6 results in loss of HSC fitness•TRAF6 maintains a minimal threshold level of IKKβ/NF-κB signaling in HSC Fang et al. identify TRAF6 as an essential regulator of hematopoietic stem cell (HSC) self-renewal and quiescence. TRAF6 preserves HSC homeostasis by maintaining a minimal threshold level of NF-κB signaling in the absence of inflammation.