St. Laurentius, Religious architectural monument in Windeck, Germany.

St. Laurentius is a neo-Romanesque church built in 1879–1880 to a design by Cologne architect August Carl Lange. Its twin octagonal spires rise 56 m above a pale stone facade; the lower storeys of the north tower survive from the 12th/13th-century predecessor. A rose window sits above the main portal, and a squat choir with a single-storey sacristy closes the east end.

Dattenfeld was first mentioned on 16 June 895 in a deed of donation to the Cassius-Stift in Bonn, which records a church with a farm there. A Romanesque predecessor was built in the 12th century and stood until 1878, when it was demolished apart from the north tower. The present church was designed by Cologne architect August Carl Lange; the foundation stone was laid on 29 April 1879 and the consecration followed in 1893.

The church is dedicated to Saint Lawrence of Rome, and its patronal feast on 10 August was the date of the new building's blessing in 1880. In the old north tower, the baptismal chapel holds a Romanesque font of the late 12th century carved from andesite, ringed by six corner columns and covered since 1962 by a lid by Hein Gernot. A reconstruction of the Dattenfeld Madonna, made in 2003 in a South Tyrolean carving workshop, stands in the south transept apse and was consecrated by Cardinal Joachim Meisner on 10 June 2006.

The church stands on rising ground above the street in Dattenfeld, a district of Windeck, with the main portal facing the street and two side portals on the north side. The baptismal chapel in the old north tower lies 16 cm below the level of the rest of the interior, so watch the step at its threshold.

The north tower's two lower storeys survive from the 12th- or 13th-century predecessor church; architect August Carl Lange raised it by one storey and closed it with a dwarf gallery so it would match the new south tower. The church is the only one in the Rhein-Sieg district with two towers.