Bank of the West was an American financial institution headquartered in San Francisco, California, United States.

[3] In 1970, Banque Nationale de Paris (BNP) established the French Bank of California.

The creation of BancWest Bancorp caused the now-called BNP Paribas's (BNPP) ownership of the holding company to fall to 45%.

BNPP also agreed not to increase its ownership of the bank holding company before November 2001.

In May 2001, the independent directors of BancWest Bancorp established a special committee that then unanimously voted to accept BNP's offer to acquire the remaining 55% of BancWest Bancorp, making the holding company a wholly owned subsidiary of BNP.

In March 2004, Bank of the West announced the purchase of Community First Bankshares, a bank holding company that operated Community First National Bank, headquartered in Fargo, North Dakota, which had 155 offices in 12 states: Arizona, California, Colorado, Iowa, Minnesota, Nebraska, New Mexico, North Dakota, South Dakota, Utah, Wisconsin, and Wyoming.

[8] In December 2005, Bank of the West bought Commercial Federal Corporation of Omaha, Nebraska.

This merger added offices in Arizona, Colorado, Iowa, Kansas, Missouri, Nebraska, and Oklahoma to Bank of the West.