St John's Archcathedral is a Catholic church within the Old Town precinct in Warsaw, Poland. The Brick Gothic structure stands on Świętojańska Street, adjacent to the Jesuit Church. St John's is one of three major cathedrals in the city, but it is the only temple that also possesses the title of an archcathedral. It is the mother church of the Archdiocese of Warsaw and one of Poland's national pantheons. Along with the old city, the church has been listed by UNESCO as a World Heritage Site.

Warsaw Old Town, also known as Old Town, and historically known as Old Warsaw, is a neighbourhood, and an area of the City Information System, in the city of Warsaw, Poland, located within the district of Śródmieście. It is the oldest portion of the city, and contains numerous historic buildings, mostly from 17th and 18th centuries, such as the Royal Castle, city walls, St. John's Cathedral, and the Barbican. The settlement itself dates back to between the 13th and 14th centuries, and was granted town privileges c. 1300.