The American Baptist Churches USA, abbreviated as ABCUSA, is a mainline Protestant denomination in the United States, and part of the Baptist tradition. The American Baptist Churches is the reorganization from 1907 of the Triennial Convention, established in 1814. It is rooted in the early English and Welsh Baptist settlers in America, especially with the foundation of Rhode Island Colony, tracing its history to the First Baptist Church in America, established by Roger Williams in 1638. The Triennial Convention became the Northern Baptist Convention in 1907, which was renamed as the American Baptist Convention from 1950 to 1972. The ABCUSA headquarters is located in King of Prussia, Pennsylvania. The American Baptist Churches cooperates with the Baptist World Alliance, the Baptist Joint Committee, and the World Council of Churches.
Although the denomination is considered mainline Protestant, one of the Seven Sisters of American Protestantism, varying theological and missional emphases may be found among its congregations, including evangelical, conservative, and charismatic orientations. In 2025, Pew Research Center published the Religious Landscape Survey, estimating that 1 percent of US adults, or 2.6 million people, self-identify as adherents of the American Baptist Churches USA.
