Gadd45a knockout inhibits cisplatin-induced cell death in the OC1 cell line. Transcriptome sequencing revealed that Gadd45a knockout suppresses the expression of CXCL family cytokines. This finding was further validated by protein-sequencing of the cell culture supernatant. Mechanistically, Gadd45a knockout specifically inhibits NF-κB1 (p105/p50) but not RELA (p65), both of which are transcription factors for CXCL family genes. Immunofluorescence staining demonstrated that Gadd45a knockout inhibits the nuclear translocation of NF-κB1 protein, but not that of RELA. In vivo, both si-Gadd45a injection into the semicircular canal and conditional knockout of Gadd45a effectively attenuated cisplatin-induced ototoxicity.