The Book of Concord (1580) or Concordia is the historic doctrinal standard of the Lutheran Church, consisting of ten credal documents recognized as authoritative in Lutheranism since the 16th century. They are also known as the symbolical books of the Evangelical Lutheran Church.

Lutheranism is a major branch of Protestantism, identifying primarily with the theology of Martin Luther, the 16th-century German monk and reformer whose efforts to reform the theology and practices of the Catholic Church launched the Protestant Reformation.