The Cathedral Church of Saint Peter and Saint Paul in the City and Diocese of Washington, commonly known as Washington National Cathedral, is an American cathedral of the Episcopal Church. The cathedral is located in Washington, D.C., the capital of the United States. The structure is of Neo-Gothic design closely modeled on English Gothic style of the late fourteenth century. It is the second-largest church building in the United States, and the third-tallest building in Washington, D.C. The cathedral is the seat of both the Presiding Bishop of the Episcopal Church, Michael Bruce Curry, and the bishop of the Diocese of Washington, Mariann Edgar Budde. Over 270,000 people visit the structure annually.The Protestant Episcopal Cathedral Foundation, under the first seven Bishops of Washington, erected the cathedral under a charter passed by the United States Congress on January 6, 1893. Construction began on September 29, 1907, when the foundation stone was laid in the presence of President Theodore Roosevelt and a crowd of more than 20,000, and ended 83 years later when the "final finial" was placed in the presence of President George H. W. Bush in 1990. Decorative work, such as carvings and statuary, is ongoing as of 2011. The Foundation is the legal entity of which all institutions on the Cathedral Close are a part; its corporate staff provides services for the institutions to help enable their missions, conducts work of the Foundation itself that is not done by the other entities, and serves as staff for the board of trustees.

The cathedral stands at Massachusetts and Wisconsin Avenues in the northwest quadrant of Washington. It is an associate member of the recently organized inter-denominational Washington Theological Consortium. It is listed on the National Register of Historic Places. In 2007, it was ranked third on the List of America's Favorite Architecture by the American Institute of Architects.