Acute myeloid leukaemia (AML) is an aggressive and deadly cancer underpinned by aberrant developmental processes that ultimately result in overproduction of immature dysfunctional cells. AML is initiated and sustained by a small population of leukaemic stem cells (LSCs) which possess unlimited self-renewal potential and have been linked with drug resistance and poor treatment outcomes. Identification of metabolic pathways that are dysregulated in LSCs offers significant promise for the development of new therapeutic strategies. Heme is an essential metabolite with broad biological activity that is required and produced by all cells. In addition to its catalytic role as a cofactor in hemoproteins, heme also directly regulates signalling and gene expression. AML biosynthesis enzymes are among the most downregulated genes during AML progression and are especially repressed in LSCs compared with more mature cells. Using a multiomic approach we analysed heme biosynthesis in mouse models, AML cell lines and patient samples and found that common AML driver genes functionally reduce heme production capacity. The low heme state in turn affects mitochondrial metabolism and drives altered gene expression patterns, in part via heme sensing transcription factors including BACH1. In proof-of concept experiments we demonstrate that low heme AML cells have increased sensitivity to inhibitors of the electron transport chain and drugs that induce ferroptosis. Using unbiased CRISPR screening methodologies we also uncovered novel biochemical pathways that are synthetic lethal with heme metabolism including, unexpectedly, N-linked glycan synthesis. Altogether, our data points to a model where the low heme state promotes metabolic and transcriptional programs that are beneficial for self-renewal but also results in vulnerabilities that can be exploited for therapeutic benefit.