Union County, Ohio, suffered a ransomware attack between May 6–18, 2025, resulting in the theft of highly sensitive personal and financial data belonging to 45,487 residents and staff. The compromised information included Social Security numbers, driver’s license numbers, financial account details, fingerprint data, medical records, and passport numbers. The breach was detected on May 18, 2025, prompting an immediate investigation with third-party cybersecurity experts and federal law enforcement. While the county secured its network and notified affected individuals by August 25, 2025, no ransomware group has yet claimed responsibility. The attack exposed critical personal data, posing severe risks of identity theft, financial fraud, and long-term reputational damage to the county and its residents. Union County, a fast-growing region with ~75,159 residents, faces potential legal, operational, and trust-related consequences due to the scale and sensitivity of the breach.