Histone deacetylases (HDACs) have been linked to a variety of cancers, and HDAC inhibitors (HDACi) are a promising class of drugs that have demonstrated anti-cancer effects. However, we have little knowledge regarding the selection and application of HDAC inhibitors to the personalized treatment of ovarian cancer (OC). Here, we report a correlation between the high expression of HDACs and poor outcomes in OC patients, which reveals that HDACi are a class of agents that show great promise for the treatment of OC. Furthermore, we found that HDACi increased both the mRNA and protein levels of DHRS2, which has been shown to be closely linked to HDACi sensitivity when it is highly expressed, especially in ovarian cancer cells. Consistently, we found that suppression of DHRS2 reduced the sensitivity of OC cells to HDAC inhibitors via attenuation of the inhibitory effects of HDAC inhibitors on Mcl-1 in vitro. Our study demonstrated that DHRS2 expression was decreased in OC tissues and that high expression of DHRS2 was correlated with better outcomes in OC patients. In addition, DHRS2 expression was closely related to the effects of chemotherapy. Our study reveals the role of DHRS2 in cell apoptosis induced by HDAC inhibitors and explores the clinical attributes of DHRS2 in OC from a new perspective, suggesting that OC patients with high DHRS2 expression may benefit from treatment with HDAC inhibitors.