American Water is an American public utility company operating in the United States and Canada. It was founded in 1886 as the American Water Works & Guarantee Company. In 1914, American Water Works and Guarantee Company became American Water Works and Electric Company. In 1947 it was reorganized as American Water Works Company, Inc. The company was a subsidiary of the German-based RWE Group from 2001 to 2008, but the company was divested on April 23, 2008 in an IPO on the NYSE.

Most of American Water's services are locally managed utility subsidiaries that are regulated by the U.S. state in which each operates. American Water also owns subsidiaries that manage municipal drinking water and wastewater systems under contract and others that supply businesses and residential communities with water management products and services. In 2003, American Water established the American Water Military Services Group, which serves as contracted water utility for several military bases in the United States. Military Services Group works with the United States Military to treat and supply water and to collect and treat wastewater for military installations all over the country. Most recently American Water Military Services Group provides services to 11 military bases.

With headquarters in Voorhees, New Jersey, American Water has about 6,800 employees and provides services to approximately 15 million people in 47 U.S. states and Ontario, Canada.

As of 2017 American Water shares are mainly held by institutional investors (Vanguard group, BlackRock, State Street Corporation and others)