METTL14 downregulation promotes MAFLD progression by driving the accumulation of S100A4-positive monocyte-derived macrophages (Mo-macs) through the MyD88/NF-κB pathway. In patients and murine models of MAFLD, METTL14 expression is significantly reduced in liver tissues, leading to increased lipid accumulation, liver injury, and fibrosis. METTL14 depletion reduces GLS2 expression via m6A-dependent regulation of YTHDF1, which contributes to an oxidative stress environment and recruits Cx3cr1+ Ccr2+ Mo-macs. These macrophages can be classified into M1-like and S100A4-positive subtypes, which activate hepatic stellate cells (HSCs) to promote fibrosis. The S100A4 expression in these macrophages is regulated by the CX3CR1/MyD88/NF-κB pathway, and restoring METTL14 or GLS2, or inhibiting this pathway, ameliorates liver injury and fibrosis. These findings suggest that METTL14 and GLS2 are potential therapeutic targets for MAFLD progression.METTL14 downregulation promotes MAFLD progression by driving the accumulation of S100A4-positive monocyte-derived macrophages (Mo-macs) through the MyD88/NF-κB pathway. In patients and murine models of MAFLD, METTL14 expression is significantly reduced in liver tissues, leading to increased lipid accumulation, liver injury, and fibrosis. METTL14 depletion reduces GLS2 expression via m6A-dependent regulation of YTHDF1, which contributes to an oxidative stress environment and recruits Cx3cr1+ Ccr2+ Mo-macs. These macrophages can be classified into M1-like and S100A4-positive subtypes, which activate hepatic stellate cells (HSCs) to promote fibrosis. The S100A4 expression in these macrophages is regulated by the CX3CR1/MyD88/NF-κB pathway, and restoring METTL14 or GLS2, or inhibiting this pathway, ameliorates liver injury and fibrosis. These findings suggest that METTL14 and GLS2 are potential therapeutic targets for MAFLD progression.