Hypoxia inducible factor-1 (HIF-1) is the main transcriptional activator of the cellular response to hypoxia and an important target of anticancer therapy. Phosphorylation by ERK stimulates the transcriptional activity of HIF-1α by inhibiting its CRM1-dependent nuclear export. Here, we demonstrate that phosphorylation by ERK also regulates the association of HIF-1α with a novel interaction partner identified as mortalin (GRP75) which mediates non-genomic involvement of HIF-1α in apoptosis. Mortalin binds specifically to HIF-1α lacking modification by ERK and their complex is localized outside the nucleus. Under hypoxia, mortalin mediates targeting of unmodified HIF-1α to the outer mitochondrial membrane and association with VDAC1 and hexokinase II, which promote production of VDAC1-ΔC and protection from apoptosis when ERK is inactivated. Under normoxia, transcriptionally inactive forms of unmodified HIF-1α or its C-terminal domain alone are also targeted to mitochondria, stimulate production of VDAC1-ΔC and increase resistance to etoposide- or doxorubicin-induced apoptosis. These findings reveal an ERK-controlled, unconventional and anti-apoptotic function of HIF-1α that may serve as an early protective mechanism upon oxygen limitation and promote cancer cell resistance to chemotherapy.