Host cell metabolism can be modulated by viral infection, affecting viral survival or clearance. Yet the cellular metabolism rewiring mediated by the N⁶-methyladenosine (m⁶A) modification in interactions between virus and host remains largely unknown. Here we report that in response to viral infection, host cells impair the enzymatic activity of the RNA m⁶A demethylase ALKBH5. This behavior increases the m⁶A methylation on α-ketoglutarate dehydrogenase (OGDH) messenger RNA (mRNA) to reduce its mRNA stability and protein expression. Reduced OGDH decreases the production of the metabolite itaconate that is required for viral replication. With reduced OGDH and itaconate production in vivo, Alkbh5-deficient mice display innate immune response–independent resistance to viral exposure. Our findings reveal that m⁶A RNA modification–mediated down-regulation of the OGDH-itaconate pathway reprograms cellular metabolism to inhibit viral replication, proposing potential targets for controlling viral infection.