interdenominational organization for Protestant youth in Canada, Mexico, and the United States. It was founded in 1881 by Francis Edward Clark (Clark, Francis Edward), who served as president until 1927. Members of the society pledged to try to make some useful contribution to the life of the church. Other churches soon organized Christian Endeavor societies, and the movement grew rapidly in the United States.

The purpose of the International Society of Christian Endeavor is “to promote an earnest Christian life among its members, to increase their mutual acquaintance, to train them for work in the church, and in every way to make them useful in the service of God and their fellow men.” The organization publishes a periodical, Christian Endeavor World, and holds conventions biennially.

The World's Christian Endeavor Union, (WCEU), organized in 1895, is a cooperative organization for Christian Endeavor groups in more than 75 countries. It holds conventions every four years. Headquarters for both organizations are in Columbus, Ohio.