Background: The cardiotoxic effects of doxorubicin (DOX), a powerful chemotherapeutic drug, are widely recognized. Cuproptosis, a unique copper-dependent form of controlled cell death, may be involved in DOX-induced cardiomyopathy, according to recent findings. This study employs both in vivo and in silico procedures to investigate the protective effects of the copper chelator penicillamine (PEN) and the role of cuproptosis in DOX-related cardiotoxicity. Methods: Thirty-two adult Sprague Dawley rats were allocated into four groups (n = 8): control, DOX, DOX+PEN, and PEN. Cardiac function was assessed via echocardiography. Serum cardiac biomarkers (LDH, CK-MB, CTnI), oxidative stress markers (SOD, GPX, MDA), and expression levels of cuproptosis-related genes (FDX1, LIAS, SLC31A1, ATP7A) were evaluated. Histopathological examinations and immunohistochemical staining for FDX1, SLC31A1, and DLAT were performed. Molecular docking simulated PEN's interaction with cuproptosis-related proteins. Network pharmacology and molecular docking studies were also conducted to identify core molecular targets and simulate PEN's binding interactions with key cuproptosis regulators. Results: DOX administration induced significant cardiac dysfunction, oxidative stress, and upregulation of cuproptosis markers. PEN treatment mitigated these effects, improved cardiac function, reduced fibrosis, and suppressed the expression of cuproptosis-related genes and proteins. Docking results confirmed strong interactions between PEN and cuproptosis-regulatory proteins. Network pharmacology revealed 14 key overlapping targets linking PEN with cuproptosis and DOX-induced cardiotoxicity. Conclusion: This study provides experimental evidence implicating cuproptosis in DOX-induced cardiomyopathy. PEN exerts cardioprotection, potentially by targeting this pathway, offering a promising therapeutic strategy.