Objectives: The tumorigenic progression of Lung adenocarcinoma (LUAD), the predominant NSCLC subtype, is predominantly driven by co-occurring mutations in KRAS proto-oncogene (KRAS)/Tumor protein p53 (TP53). However, their impact on tumor microenvironment (TME) heterogeneity, particularly neutrophil dynamics, remains poorly understood. This present study aims to elucidate how KRAS/TP53 mutations reprogram the TME and develop a neutrophil-centric prognostic signature for LUAD. Methods: Leveraging single-cell RNA sequencing data and transcriptome data, neutrophil subpopulations were identified using Seurat and CellChat R packages, with trajectory analysis via Monocle2 R package. High-dimensional weighted gene co-expression network analysis (hdWGCNA), univariate Cox regression, and least absolute shrinkage and selection operator (LASSO) regression analyses were employed to generate a prognostic signature. Functional validation included Ras homolog family member V (RHOV) knockdown in A549/H1299 cells using siRNA, were assessed by cell counting kit 8 (CCK8) assay, wound healing assay, and transwell assay. Results: KRAS/TP53-mutated LUAD exhibited increased neutrophil infiltration, particularly IS MUT subtypes with enhanced OSM/CALCR/IL-1 signaling. A five-gene prognostic signature (MS4A1, ANLN, FAM83A, RHOV, KRT6A) stratified patients into high-and low-risk groups with divergent overall survival in the TCGA-LUAD cohort (p < 0.0001). AUCs achieved 0.73, 0.70, and 0.66 at 1-, 3-, and 5-year, respectively. External validation in immunotherapy cohorts (IMvigor210, GSE78220) confirmed the fine predictive capability of the prognostic signature in predicting treatment response. An integrated prognostic nomogram combining clinicopathological features and risk score further improved its clinical utility. Pseudotime analysis found that RHOV was essential for the growth of lung epithelial cells. RHOV knockdown significantly reduced the proliferation, migration, and invasion capabilities of A549/H1299 cells in vitro. Conclusion: KRAS/TP53 mutations may drive neutrophil heterogeneity in the TME of LUAD, addressing prognostic and therapeutic value. The five-gene signature and RHOV targeting offer translational relevance for risk stratification and therapy. These findings bridge genomic alterations with TME remodeling, advancing precision oncology in LUAD.