Abstract Gene copy number alterations, tumor cell stemness, and development of platinum chemotherapy resistance contribute to high-grade serous ovarian cancer (HGSOC) recurrence. Stemness phenotypes involving Wnt-beta-catenin, aldehyde dehydrogenase activities, intrinsic platinum resistance, and tumorsphere formation are here associated with spontaneous genetic gains in KRAS, MYC, and FAK (KMF) genes, in a new aggressive murine model of ovarian cancer. Noncanonical signaling via FAK sustained KMF and human tumorsphere proliferation as well as resistance to cisplatin cytotoxicity. Platinum-resistant tumorspheres can acquire a dependence on FAK for growth. Accordingly, increased FAK tyrosine phosphorylation was observed within HGSOC patient tumors surviving neoadjuvant chemotherapy. Combining a FAK inhibitor with platinum overcame chemoresistance, triggering tumor cell apoptosis. FAK transcriptomic analyses across knockout and reconstituted cells identified 135 genes elevated by a FAK activity-dependent, beta-catenin, and Myc signaling axis including pluripotency and DNA repair genes. Identified target increases in HGSOC tumors may reflect oncogenic FAK signaling. Citation Format: Carlos J. Díaz Osterman, Duygu Ozmadenci, Elizabeth G. Kleinschmidt, Kristin N. Taylor, Allison M. Barrie, Shulin Jiang, Lisa M. Bean, Florian J. Sulzmaier, Jian Li, Xiao Lei Chen, Guo Fu, Marjaana Ojalill, Pekka Rappu, Jyrki Heino, Adam A. Mark, Guorong Xu, Kathleen M. Fisch, David T. Weaver, Jonathan A. Pachter, Balázs Győrffy, Michael T. McHale, Denise C. Connolly, Alfredo Molinolo, Dwayne G. Stupack, David D. Schlaepfer. FAK activity sustains intrinsic and acquired ovarian cancer resistance to platinum chemotherapy [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A61.