St. Johannes Evangelist, Catholic church in Sassenberg, Germany.

St. Johannes Evangelist is a three-nave hall church built from 1670 to 1678 in Sassenberg, its plastered brick walls and red-tiled saddle roof oriented south rather than east. Stepped buttresses divide the long sides, and the interior's cross vaults rest on four massive round columns. The north tower, finished in 1914, reuses the old baroque portal on its north side.

The parish was long served by St. Laurentius in Warendorf before a church could be built in Sassenberg; the foundation stone was laid on 24 April 1670 and Prince-Bishop Christoph Bernhard von Galen consecrated the church on 1 May 1678. Until the early 20th century it had only a small roof turret; the north tower, designed by diocesan architect Wilhelm Sunder-Plassmann, was completed on 29 June 1914 after a neighbouring tavern was bought and demolished.

Two baroque side altars from the 17th century stand in the side aisles with intricate carved details. These religious artworks still shape the interior character today and draw visitors into quiet contemplation.

The church is not oriented to the east but to the south, so the tower stands on the north side, where the old baroque portal was reused. The tower has an external balcony at bell level and clock faces on its three free-standing sides. The nave is entered through baroque portals on the north and west, decorated with columns and the von Galen coat of arms.

The interior was enriched between 2008 and 2010 with a modern organ specially built by Hermann Eule Orgelbau Bautzen to contemporary standards. With 28 registers, this instrument marries traditional craftsmanship with modern acoustics.