United States National Bank of San Diego (USNB) was a large California bank seized by the Federal Deposit Insurance Corporation (FDIC) in 1973 due to the malfeasance of its owner, C. Arnholt Smith (1899–1996). It was, at the time, the largest bank ever seized by the FDIC. USNB's assets and domestic branches were taken over by Crocker National Bank, which later merged into Wells Fargo.