St. Martin, Roman Catholic church in Giesen, Germany

St. Martin is a Roman Catholic church in Giesen. Its late Romanesque chapel, built around 1250, is a rubble-stone building with a west tower topped by a slate pyramid. In 1971–1972 an eastern cross-wing by Hubert Ohmes was added, incorporating the old tower and older roof parts.

The chapel originated in the 13th century under the jurisdiction of the Archdeacon of St. Andreas in Hildesheim. It later became an independent parish church to serve the expanding Catholic communities in the area.

The chapel became a Pfarrvikarie and parish community in 1941, not 1973, when the potash industry drew more Catholics to Klein and Groß Giesen. The 1973 date marks the consecration of the enlarged church by Bishop Heinrich Maria Janssen. Since 2014 St. Martin has been a filial church of the St. Vitus parish based in Giesen.

The church stands in Klein Giesen, now part of the municipality of Giesen. The west tower with its green copper steeple and the 1971/72 eastern extension are visible from the outside; the interior is open for services. The site is a listed monument together with the neighbouring chapel, parish house/schoolhouse and cemetery.

Local residents in the 17th century requested permission to hold services on site because winter journeys to other churches were dangerous. This request eventually led to the chapel gaining greater importance and later expansion.