A necropsy was performed on a captive-born, 10-yr-old male Atlantic bottlenose dolphin (Tursiops truncatus) after it died acutely. Gross necropsy findings revealed hemorrhage within the right cerebrum, right cerebellum, and right eye. Histopathologic findings revealed a moderate multifocal acute necrotizing meningoencephalitis with intralesional fungal hyphae. Several pieces of cerebrum and cerebellum and cerebrospinal fluid were sent to the Fungus Testing Laboratory in San Antonio, Texas (U.S.A.). The culture yielded Fusarium oxysporum, which was confirmed by internal transcribed spacer and D1-D2 sequencing. Fusarium oxysporum infection has been reported in marine mammals. No cases of noncutaneous F. oxysporum infection in a cetacean that was not on long-term antimicrobials have been reported in the literature.