The company was founded in 1913 as City Center Bank by William T. Kemper with $1,100 in first-day deposits. William's son R. Crosby Kemper became president in 1919. Crosby's brother, James M. Kemper, worked on building Commerce Bancshares. City Center Bank started what is claimed to be the first "drive-up" window in 1928.

In 1934, the bank was renamed City National Bank & Trust Company, and opened its headquarters in downtown Kansas City at 928 Grand Boulevard. As banking laws changed, the bank formed a holding company, Missouri Bancshares, Inc. in 1969. It changed its name to United Missouri Bancshares, Inc. in 1971 as it became a multibank holding company, and City National changed its name to United Missouri Bank. In 1994, the bank again changed its name to UMB Financial Corporation to better suit its expanding, multi-state business. In 2003, it began being traded on NASDAQ.