Renal fibrosis is a crucial factor in the progression of chronic kidney diseases. Previous studies have suggested that apigenin (API) has potential in ameliorating renal fibrosis, but its therapeutic mechanism remains unclear. This study aims to elucidate the mechanisms by which API treats renal fibrosis using network pharmacology and experimental validation. Initially, we used the Traditional Chinese Medicine Systems Pharmacology (TCMSP) Database and GeneCards database to identify molecular targets of API and associated genes. Next, we constructed a network of API-renal fibrosis targets, followed by protein–protein interaction (PPI) analysis. Subsequent analyses, such as Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, were performed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID). We also performed molecular docking studies to explore API’s interactions with key proteins. To validate API’s mechanism in treating renal fibrosis, we used a Human Kidney-2 (HK-2) cell model of epithelial-mesenchymal transition (EMT) induced by transforming growth factor-β1 (TGF-β1). We identified 77 API target genes, 8434 renal fibrosis target genes, and 64 intersection genes, which were primarily enriched in nuclear factor kappa-B (NF-κB) and Phosphatidylinositide 3-kinases/protein kinase B (PI3K-AKT) pathways. API significantly inhibited EMT in TGF-β1-induced HK-2 cells by regulating the expression of α-Smooth muscle actin (α-SMA) and E-cadherin and suppressing the protein expression of p-PI3K, p-AKT, and p-P65, which are related to the PI3K-AKT and NF-κB pathways. However, co-administration of the PI3K agonist 740Y-P counteracted API’s inhibitory effects on these protein expressions. In summary, these findings highlight API’s therapeutic potential in treating renal fibrosis by modulating EMT in renal tubular epithelial cells via the PI3K-AKT and NF-κB pathways.