Background: The pentose phosphate pathway (PPP) is a critical metabolic pathway that generates NADPH and ribose-5-phosphate for nucleotide biosynthesis and redox homeostasis. In this study, we investigated a potential regulatory role for Krüppel-like factor 8 (KLF8) in the control of PPP in lung adenocarcinoma (LUAD) cells. Methods: Based on a comprehensive set of experimental approaches, including cell culture, molecular techniques, and functional assays, we revealed a novel mechanism by which KLF8 promotes the activation of glucose-6-phosphate dehydrogenase (G6PD), a component enzyme in the PPP. Results: Our findings demonstrate that KLF8 inhibits the acetylation of G6PD, leading to its increased enzymatic activity. Additionally, we observed that KLF8 activates the transcription of SIRT2, which has been implicated in regulating G6PD acetylation. These results highlight the interplay between KLF8, G6PD, and protein acetylation in the regulation of PPP in LUAD. Conclusions: Understanding the intricate molecular mechanisms underlying the metabolic reprogramming driven by KLF8 in lung cancer provides valuable insights into potential therapeutic strategies targeting the PPP. This study emphasizes the significance of KLF8 as a key modulator of metabolic pathways and indicates the potential of targeting the KLF8-G6PD axis for lung cancer treatment.