Background <p>Radioresistance is a major obstacle in antitumor therapies. This study explores the effects and functional mechanisms of zDHHC palmitoyltransferase 13 (ZDHHC13) on radioresistance in nasopharyngeal carcinoma (NPC).</p> Methods <p>Bioinformatic and tumor tissue microarray analyses were performed to identify the expression pattern of ZDHHC13 in NPC. The parental C666-1 and HNE1 NPC cell lines were exposed to radiation to generate resistant cell lines (C666-1R and HNE1R). ZDHHC13 was silenced in these cell lines, followed by cell survival, proliferation, and apoptosis assays. The levels of copper ion metabolism-related factors, Cu⁺, and oxidative stress in the cells were determined to analyze cuproptosis activity. The interaction between ZDHHC13 and ferredoxin 1 (FDX1) was examined using immunoprecipitation and colocalization assays. Xenograft tumor models were established in mice for in vivo verification.</p> Results <p>ZDHHC13 was abundantly expressed in radioresistant NPC cells. ZDHHC13 knockdown enhanced the radiosensitivity of C666-1R and HNE1R cells, reduced cell proliferation, and promoted apoptosis under 5&#xa0;Gy radiation exposure. Factors implicated in copper ion reduction, including FDX1, reduced in resistant cell lines. ZDHHC13 knockdown improved Cu⁺ levels and cuproptosis in cells. Treatment with tetrathiomolybdate, a copper chelator, blocked the oxidative stress and cuproptosis in C666-1R and HNE1R cells enhanced by ZDHHC13 silencing. Palmitoylation of FDX1 increased in radioresistant cells and decreased upon ZDHHC13 silencing. FDX1 silencing reduced cuproptosis and radiosensitivity in NPC cells.</p> Conclusion <p>This study suggests that ZDHHC13 prevents cuproptosis and enhances radioresistance in NPC cells by modulating FDX1 palmitoylation.</p> Graphical Abstract <p></p>