James Michael Curley (November 20, 1874 – November 12, 1958) was an American Democratic politician from Boston, Massachusetts. He served four terms as mayor of Boston; from 1914 to 1955, he ran for mayor in every election for which he was legally qualified. He also served a single term as governor of Massachusetts, characterized by one biographer as "a disaster mitigated only by moments of farce" for its free spending and corruption. He is remembered as one of the most colorful figures in Massachusetts politics.

Curley also served two terms, separated by 30 years, in the United States House of Representatives and, in his early career, served in the Boston Common Council, Boston Board of Aldermen, and Massachusetts House of Representatives. He was twice convicted of criminal behavior and notably served time in prison during his last term as mayor.

Curley was immensely popular with his fellow working-class Roman Catholic Irish Americans. During the Great Depression, he enlarged Boston City Hospital, expanded the city's public transit system, funded projects to improve roads and bridges, and improved the neighborhoods with beaches and bathhouses, playgrounds and parks, public schools, and libraries, all the while collecting graft and raising taxes. He was a leading and at times divisive force in the Massachusetts Democratic Party, challenging Boston's ward bosses and the party's white Anglo-Saxon Protestant leadership at the local and state levels. His political tactics, which tended to drive businesses and economically successful people from the city, damaging the local economy, have become an object of study for economists and political scientists.