Groschlag was a family of German nobility of the County of Mark, extinct in 1799.
The knights of Groschlag were vogts (reeves) at Eppertshausen in the Carolingian Empire.
In the 14th century, they were employed as castle officials in Dieburg in the Archbishopric of Mainz. They entered into a long-lasting territorial feud with the counts of Hanau. In the 1355 Weistum of Babenhausen, the counts of Hanau are represented as the highest-ranking nobility of the Mark, with the knights of Groschlag following in second place.
In the 17th century, the Groschlag family married into the powerful Schönborn aristocracy, rising to higher status in the principality of Mainz. The male line of the Groschlags was extinct in 1799, with a surviving daughter, the Duchess of Lerchenfeld-Köfering inheriting Eppertshausen.