〔Abstract〕 Objective To investigate the functional role and underlying molecular mechanisms of fumarylacetoacetate hydrolase (FAH) in the progression of glioblastoma (GBM). Methods Differential expression analysis was performed on the TCGA-GBM, GSE4290, and GSE116520 datasets. Weighted gene co-expression network analysis (WGCNA) was used to identify key modules, and Cox regression and risk modeling were used to screen prognostic genes. Immune infiltration analysis of prognostic genes was carried out by using single-cell RNA sequencing panels. The clinical expression signature of FAH in GBM was analyzed in the TCGA and HPA databases. The functional role of FAH was validated by in vitro and in vivo experiments, and pathway analysis was performed to explore the underlying mechanisms. Results A total of 152 overlapping genes were identified across the three GBM datasets. WGCNA revealed that the turquoise module was most strongly associated with tumor purity, stromal score, immune score, and ESTIMATE score (P < 0.001). Compared with normal tissues, three prognostic genes (CTSD, FAH, and THBD) were upregulated in GBM and correlated with immune infiltration (P < 0.05). FAH mRNA and protein levels were elevated in GBM tissues relative to normal tissues, and its expression was significantly associated with age stratification and TP53 mutation (P < 0.05). CCK-8 assay results showed that, compared with the shNC group, the proliferative activity of GBM cells in the shFAH group was reduced (P < 0.001). Transwell migration and invasion assays demonstrated that, relative to the shNC group, the numbers of migrated and invaded cells in the shFAH group decreased (P < 0.05). Western blot analysis revealed that the protein expression levels of PI3K, p-AKT, and p-mTOR in the shFAH group decreased compared with those in the shNC group (P < 0.05). In vivo subcutaneous xenograft experiments further confirmed that tumor volume and weight significantly decreased in the shFAH group compared with the shNC group (P < 0.001). Conclusion FAH promotes GBM progression by activating the PI3K/AKT/mTOR signaling pathway and may serve as a potential therapeutic target for GBM.