James "Jamie" Dimon (/ˈdaɪmən/; born March 13, 1956) is an American business executive. He is chairman, president and chief executive officer of JPMorgan Chase, largest of the Big Four American banks, and previously served on the Board of Directors of the Federal Reserve Bank of New York. Dimon was named to Time magazine's 2006, 2008, 2009, and 2011 lists of the world's 100 most influential people. He was also named to Institutional Investor's Best CEOs list in the All-America Executive Team Survey from 2008 through 2011.

He received a $23 million pay package for fiscal year 2011, more than any other bank CEO in the United States. Dimon received $20 million in compensation for his work in fiscal year 2013.

In the case of the 2012 JPMorgan Chase trading loss, according to a US Senate report published in March 2013 after 9 months of investigation, Dimon misled investors and regulators in April as losses rose dangerously to $6.2 billion on a “monstrous” derivatives bet made by the so-called "London Whale" Bruno Iksil.