Old St Paul's Cathedral was the cathedral of the City of London that, until the Great Fire of 1666, stood on the site of the present St Paul's Cathedral. Built from 1087 to 1314 and dedicated to Saint Paul, the cathedral was perhaps the fourth church at Ludgate Hill.Work on the cathedral began after a fire in 1087. Work took more than 200 years, and was delayed by another fire in 1135. The church was consecrated in 1240, enlarged in 1256 and again in the early 1300s. At its completion in the mid-1300s, the cathedral was one of the longest churches in the world, had one of the tallest spires and some of the finest stained glass.

The presence of the shrine of Saint Erkenwald made the cathedral a site of pilgrimage. In addition to serving as the seat of the Diocese of London, the building developed a reputation as a social hub, with the nave aisle, "Paul's walk", known as a business centre and a place to hear the gossip on the London grapevine. After the Reformation, the open-air pulpit in the churchyard, St Paul's Cross, became the place for radical evangelical preaching and Protestant bookselling.

The cathedral was already in severe structural decline by the early 1600s. Restoration work begun by Inigo Jones in the 1620s was temporarily halted during the English Civil War (16421651). In 1666, further restoration was in progress under Sir Christopher Wren when the cathedral was devastated in the Great Fire of London. At that point, it was demolished, and the present cathedral was built on the site.

In architecture, a steeple is a tall tower on a building, topped by a spire and often incorporating a belfry and other components. Steeples are very common on Christian churches and cathedrals and the use of the term generally connotes a religious structure. They might be stand-alone structures, or incorporated into the entrance or center of the building.