Tumor cells surviving hypoxic stress acquire the ability to drive cancer progression. To explore the contribution of dehydrogenases to the low oxygen concentration response, we used siRNAs targeting 163 dehydrogenase‐coding genes and discovered that glutamate dehydrogenase 1 (GDH1) plays a critical role in regulating colorectal cancer (CRC) cell survival under hypoxia. We observed that GDH1 deficiency had an inhibitory effect on CRC occurrence and impaired hypoxia‐inducible factor 1‐alpha (HIF‐1α) stability even under hypoxia. Mechanistically, hypoxia triggered p300 recruitment to GDH1, promoting its acetylation at K503 and K527. GDH1 acetylation at K527 induced the formation of a GDH1 complex with EGLN1/HIF‐1α; in contrast, GDH1 acetylation at K503 reinforced its affinity for α‐ketoglutarate (αKG), and glutamate production. In line with this view, αKG is a product of GDH1 under normoxia, but hypoxia stimulation reversed GDH1 enzyme activity and αKG consumption by the EGLN1/HIF‐1α complex, increasing HIF‐1α stability and promoting CRC progression. Clinically, hypoxia‐modulated GDH1 AcK503/527 can be used as a biomarker of CRC progression and is a potential target for CRC treatment. Synopsis: This study identifies αKG metabolic enzyme glutamate dehydrogenase 1 (GDH1) as a major factor controling colorectal cancer (CRC) by facilitating HIF‐1a‐dependent cancer signaling. GDH1 is required for hypoxia response in CRC cells and associated with poor prognosis in patients.GDH1 depletion in the mouse intestine impairs CRC formation.Hypoxia‐induced acetylation of GDH1 by p300 is required for HIF‐1α stability.Hypoxia‐induced GDH1 acetylation at K503 reverses its dehydrogenase activity.Hypoxia‐induced GDH1 acetylation at K527 anchors GDH1 to the EGLN1/HIF‐1α complex.GDH1 acetylation is required for solid tumor formation and correlates with poor CRC prognosis. [ABSTRACT FROM AUTHOR]