FETPY, an organo-diiron(I) complex, showed strong cytotoxicity across a panel of human and mouse cancer cell lines, combined with an outstanding selectivity compared to nonmalignant cells. Enhanced iron uptake in aggressive, low-differentiated cell lines, caused membrane lipid peroxidation, which resulted in ferroptosis in human ovarian cancer cells. FETPY induced significant morphological changes in murine B16-F1 and B16-F10 melanoma cells, leading to senescence and/or trans-differentiation into Schwann-like cells, thus significantly reducing their tumorigenic potential. Additionally, FETPY substantially suppressed tumor growth in low- and high-grade syngeneic melanoma models when administered in a therapeutic regimen. FETPY is featured by satisfactory water solubility (millimolar range), an amphiphilic character (Log Pow = -0.17), and excellent stability in a biological medium (DMEM). These important requisites for drug development are rarely met in iron complexes investigated so far as possible anticancer agents. Overall, FETPY holds promise as a safe and potent targeted antitumor agent.