Oncolytic virotherapy is a promising approach for treating drug-resistant ovarian cancer, but clinical efficacy has been hindered because the immune system quickly recognizes and clears the therapeutic virus. To overcome this barrier, stem cells can be used to shield the virus from the immune system, thereby enabling improved viral delivery to tumors. However, obtaining an adequate, reproducible stem cell supply has been a significant challenge when implementing this viral delivery solution. Here, we demonstrate the ability of an “off-the-shelf” stem cell line line to protect oncolytic viral cargo from immune defenses present within patient ascites fluid. The stem cells also improve delivery to tumors within preclinical ovarian cancer models. The viral payload used in this study is an adenovirus, specifically engineered to infect only tumors. We found this viral agent was effective against cisplatin-resistant ovarian tumors and could be used as an adjunct treatment with cisplatin to decrease tumor burden without increasing toxicity. This report suggests NSC-delivered CRAd-S-pk7 virotherapy holds promise for improving clinical outcome, reducing toxicities, and improving quality of life for patients with advanced ovarian cancer.