The biggest temple in Hamm is the Protestant St. Paul's Church, located on Market Square. It is believed that the predecessor of the present church was built shortly after the city was founded in the XIII century. It got its present name only in 1912. Before the Reformation it was dedicated to the two patron saints of the city - George and Lawrence and was called simply Big Church for several centuries.
The high building of St Paul's is Hamm’s oldest construction, which went through several major fires in the Middle Ages and in the XVIII century. As a result of numerous rearrangements, the original appearance of the church has long been lost. In 2007, the church tower got the first clock throughout its history. The church’s main interior decoration is the three stone epitaph, preserved from the XVII-XVIII centuries.