Mellrich was first mentioned in documents in 1177. It has been the seat of old noble families since the 12th century. A fortified castle near Eggeringhausen, east of Mellrich, was built around 1382 as the ancestral seat. Mellrich is an agricultural village and covers an area of 749 ha. Together with the villages of Altenmellrich, Klieve, Robringhausen, Uelde and Waltringhausen it forms the parish of Mellrich. The center of the village is the parish church of St. Alexander (built in 1846), here in 1964 the interior (round vault removed and a flat ceiling installed). In 1990 the exterior of the Romanesque-Classical parish church of St. Alexander was renovated. The former vicarage (around 1760), was the birthplace of the Bishop of Paderborn Franz Drepper (1845 - 1855) and is now a parish and youth home.