In this study, we have determined the anticancer activity of doxorubicin (Dox)-loaded DNA/gold nanoparticle (AuNP) nanocarrier (Dox-DNA-AuNP) for the treatment of ovarian cancer. The anticancer effect of Dox-DNA-AuNP was evaluated in vitro using the EZ-Cytox cell viability assay on three human ovarian cancer cell lines, SK-OV-3, HEY A8, and A2780. Dox-DNA-AuNP exhibited outstanding activity with good IC₅₀ values of 4.8, 7.4, and 7.6 nM for SK-OV-3, HEY A8, and A2780, respectively. In vivo evaluation further demonstrated the superior anticancer effects of Dox-DNA-AuNP by inhibiting tumor growth compared to free Dox in an established SK-OV-3 xenograft mice model. Dox-DNA-AuNP showed about a 2.5 times higher tumor growth inhibition rate than free Dox. Furthermore, the immunohistochemical analysis of Ki67 antigen expression showed the lowest number of proliferative cells in the ovarian tumor tissue treated with Dox-DNA-AuNP. These results suggest Dox-DNA-AuNP might be a potential effective agent in ovarian cancer chemotherapy.