Doxorubicin (DOX) is the most used chemotherapeutic agent for treating solid tumors. DOX treatment may lead to testicular damage using oxidative stress, resulting in infertility. These adverse effects may be prevented by the activation of antioxidant systems. Oleuropein (OLE) is a powerful flavonoid with several ameliorative effects, including antioxidative, antiproliferative, and anti-inflammatory. It would be more efficient and applicable in treating chronic human diseases if its poor bioavailability improves with a nano-delivery system. The current study aims to assess the histopathological changes and antioxidative effects of OLE loaded with silver nanoparticles oleuropein (OLE-AgNP) on the testicular injury triggered by DOX in rats. Forty-eight male albino rats were randomly divided into six groups as follows: the control, DOX (2.5 mg/kg), OLE (50 mg/kg), AgNP (100 mg/kg), OLE + AgNP (50 mg/kg), OLE (50 mg/kg) + DOX (2.5 mg/kg), AgNP (100 mg/kg) + DOX (2.5 mg/kg), and OLE-AgNP (50 mg/kg) + DOX (2.5 mg/kg) for 11 days. Oxidative stress, inflammation, apoptosis, endoplasmic reticulum stress markers, sperm analysis, and histopathological analyses were performed on testicular tissues taken from rats decapitated after the applications and compared between the experimental groups. The tissue MDA level was lower in the OLE and OLE+AgNP-treated groups than in the DOX-treated group. In addition, SOD and GSH levels significantly increased in both the OLE and OLE+AgNP-treated groups compared to the DOX group. Both OLE and OLE+AgNP, particularly OLE+AgNP, ameliorated DOX-induced testicular tissue injury, as evidenced by reduced injury and improved seminiferous tubules and spermatocyte area. In addition, OLE and OLE+AgNP, especially OLE+AgNP, inhibited DOX-induced testicular tissue inflammation, apoptosis, and endoplasmic reticulum stress. The findings suggest that nanotechnology and the production of OLE+AgNP can ameliorate DOX-induced testicular damage.