Capital One Financial Corp. (NYSE: COF) is a U.S.-based bank holding company specializing in credit cards, home loans, auto loans, banking and savings products. A member of the Fortune 500, the company helped pioneer the mass marketing of credit cards in the early 1990s, and it is now the fourth-largest customer of the United States Postal Service and has the fifth-largest deposit portfolio in the United States.^{[clarification needed]}

It has its corporate offices in Tysons Corner, unincorporated Fairfax County, Virginia, near McLean.

Capital One was founded in 1988 by Richard Fairbank and Nigel Morris as a spin-off of Richmond, Virginia-based Signet Banking Corp (which was subsequently acquired in 1997 by First Union Corporation, which merged with Wachovia in 2001 and is now part of Wells Fargo).

Capital One entered the retail banking market with its acquisition of New Orleans, Louisiana-based Hibernia National Bank in 2005 and Melville, New York-based North Fork Bancorporation in 2006. North Fork Bank and Superior Savings of New England, both subsidiaries of North Fork Bancorporation, began using the branding of Capital One Bank on March 10, 2008. On December 4, 2008, Capital One announced it would purchase Chevy Chase Bank for US$520 million.