A church dedicated to St. Laurentius was first mentioned in a document from 1196.
It was a Gothic hall church with two naves, which was destroyed when the town burnt in 1657 due to the Second Northern War.
The church was rebuilt only provisionally.
The cloisters survived and are the only medieval building left in Itzehoe.

The present church was built from 1716 to 1718 in Baroque style.
The tower was first only slightly higher than the church.
The present tower was built from 1894 to 1896 after designs by Johannes Otzen.
It is 79.45 metres (260.7 ft) high, crowned with an onion dome and four corner towers, and was equipped with a viewing platform.
The tower was severely damaged by a storm on 8 January 2002.
The restoration was completed in 2005.

Below the church, ladies (Stiftsdamen) of the Itzehoe Abbey and members of the noble family of Rantzau were buried in metal sarcophages, including:
Dorothea of Rantzau née of Ahlefeldt (1586–1647)
her daughter, Dorothea of Rantzau (1619–1662)
the daughter's husband, Reichsgraf Christian of Rantzau (1614–1663)
Dorothea Benedicta of Rantzau (1696)
Abbess Metta Christina of Ahlefeldt (1763)
A church dedicated to St. Laurentius was first mentioned in a document from 1196. It was a Gothic hall church with two naves, which was destroyed when the town burnt in 1657 due to the Second Northern War. The church was rebuilt only provisionally. The cloisters survived and are the only medieval building left in Itzehoe.
The present church was built from 1716 to 1718 in Baroque style. The tower was first only slightly higher than the church. The present tower was built from 1894 to 1896 after designs by Johannes Otzen. It is 79.45 metres (260.7 ft) high, crowned with an onion dome and four corner towers, and was equipped with a viewing platform. The tower was severely damaged by a storm on 8 January 2002. The restoration was completed in 2005.
Below the church, ladies (Stiftsdamen) of the Itzehoe Abbey and members of the noble family of Rantzau were buried in metal sarcophages, including:
Dorothea of Rantzau née of Ahlefeldt (1586–1647)
her daughter, Dorothea of Rantzau (1619–1662)
the daughter's husband, Reichsgraf Christian of Rantzau (1614–1663)
Dorothea Benedicta of Rantzau (1696)
Abbess Metta Christina of Ahlefeldt (1763)
St. Laurentii, Itzehoe