The Gustav-Adolf-Werk (GAW) is a society under the roof of the Evangelical Church in Germany (EKD) which has for its object the aid of feeble sister churches and congregations. It is responsible for the taking care of the diaspora work of the EKD, in cooperation with the EKD itself, its member churches and congregations. The organization started with a focus on the diaspora, but has separate branches internationally in the meanwhile. The organization in Austria is still called the Gustav-Adolf-Verein, which was the original name in Germany as well. Further terms used for the GAW in the past include Gustavus Adolphus Union, Gustav-Adolf-Stiftung and Evangelischer Verein der Gustav-Adolf-Stiftung.

Gustavus Adolphus, also known in English as Gustav II Adolf or Gustav II Adolph, was King of Sweden from 1611 to 1632, and is credited with the rise of Sweden as a great European power. During his reign, Sweden became one of the primary military forces in Europe during the Thirty Years' War, helping to determine the political and religious balance of power in Europe. He was formally and posthumously given the name Gustavus Adolphus the Great by the Riksdag of the Estates in 1634.