Cisplatin is a widely used chemotherapeutic drug that can induce ovarian damage. Icariin (ICA), a natural antioxidant derived from Epimedium brevicornum Maxim., has been found to protect against organ injury. The aim of the present study was to investigate whether ICA can exert an ovarian-protective effect on cisplatin induced premature ovarian failure (POF) and the underlying mechanism involved. The preventive effect of ICA was evaluated using body weight, the oestrous cycle, ovarian histological analysis, and follicle counting. ICA treatment increased body weight, ovarian weight, and the number of follicles and improved the oestrous cycle in POF mice. ICA reduced cisplatin-induced oxidative damage and upregulated the protein expression levels of Nrf2, GPX4 and HO-1. Moreover, ICA reduced the expression levels of Bax and γH2AX and inhibited ovarian apoptosis. In addition, ICA activated the Nrf2 pathway in vitro and reversed changes in the viability of cisplatin-induced KGN cells, reactive oxygen species (ROS) levels, lipid peroxidation, and apoptosis, and these effects were abrogated when Nrf2 was knocked down or inhibited. Molecular docking confirmed that ICA promotes the release of Nrf2 by competing with Nrf2 for binding to Keap1. The inhibitory effects of ICA on cisplatin-induced oxidative stress, ferroptosis, and apoptosis may be mediated by its modulatory effects on the Nrf2 pathway, providing a novel perspective on the potential mechanisms by which ICA prevents POF.