The Second Church was a congregation active during 1649–1970, which occupied a number of locations around Boston, Massachusetts. It was first a Congregational church, and then beginning in 1802, a Unitarian church. In 1970, it merged with Boston's First Church.
Its locations in Boston included North Square, Hanover Street, Copley Square, and the Fenway. Its ministers included Michael Powell, Increase Mather, Cotton Mather, and Ralph Waldo Emerson.