Acetyl-CoA carboxylase (ACC) is the rate-limiting enzyme in de novo fatty acid synthesis, and its ACC1 isoform is overexpressed in pancreatic and various other cancers. The activity of many oncogenic signaling molecules, including WNT and Hedgehog (HH), is post-translationally modified by lipidation. Here, we report that inhibition of ACC by a small molecule inhibitor, BAY ACC002, blocked WNT3A lipidation, secretion, and signaling. In pancreatic cancer cells, where WNT and HH are key oncogenic drivers, ACC inhibition simultaneously suppressed WNT and HH signaling, and led to anti-proliferative effects. Treatment with ACC inhibitors blocked tumor growth and converted the poorly differentiated histological phenotype to epithelial phenotype in multiple cell line-based and patient-derived pancreatic cancer xenograft models. Together, our data highlight the potential utility of ACC inhibitors for pancreatic cancer treatment, and provide novel insight into the link between upregulated de novo fatty acid synthesis in cancer cells, protein lipidation, and oncogenic signaling.