The American Express Company (Amex) is an American multinational corporation specialized in payment card services headquartered at 200 Vesey Street in the Battery Park City neighborhood of Lower Manhattan in New York City. The company was founded in 1850 and is one of the 30 components of the Dow Jones Industrial Average. The company's logo, adopted in 1958, is a gladiator or centurion whose image appears on the company's well-known traveler's cheques, charge cards, and credit cards.

During the 1980s, Amex invested in the brokerage industry, acquiring what became, in increments, Shearson Lehman Hutton and then divesting these into what became Smith Barney Shearson (owned by Primerica) and a revived Lehman Brothers. By 2008 neither the Shearson nor the Lehman name existed.In 2016, credit cards using the American Express network accounted for 22.9% of the total dollar volume of credit card transactions in the United States. As of December 31, 2019, the company had 114.4 million cards in force, including 54.7 million cards in force in the United States, each with an average annual spending of $19,972.In 2017, Forbes named American Express as the 23rd most valuable brand in the world (and the highest within financial services), estimating the brand to be worth US$24.5 billion. In 2020, Fortune magazine ranked American Express at number 9 on their Fortune List of the Top 100 Companies to Work For in 2020 based on an employee survey of satisfaction.