Lung adenocarcinoma (LUAD) is the most dominant histological subtype of lung cancer and one of the most lethal malignancies. The identification of novel therapeutic targets is required for the treatment of LUAD. Here, we showed that MYC-associated zinc-finger protein (MAZ) is upregulated in LUAD tissues. MAZ expression levels are inversely correlated with patient survival. Silencing of MAZ decreased tumor proliferation and the expression of pro-tumorigenic chemokines and Galectin-9 (Gal-9), an immune checkpoint molecule. The pro-tumorigenic chemokines and Gal-9 induce immune suppression by recruitment of myeloid cells and inhibition of T cell activation, respectively. Mechanistically, MAZ transcriptionally regulates KRAS expression and activates its downstream AKT-NF-κB signaling pathway, which is crucial for tumor progression and immune evasion. Additionally, in vivo animal models and bioinformatic analyses indicated that MAZ suppression could enhance the efficacy of immune checkpoint blockade (ICB) therapy for LUAD. Overall, our results suggest that MAZ plays an important role in regulating cell proliferation and immune evasion via KRAS/AKT/NF-κB signaling in LUAD. Our findings offer a candidate molecular target for LUAD therapy, with implications for improving the efficacy of ICB therapy.