Grosthuizen is a village in the Dutch province of North Holland.
It is a part of the municipality of Koggenland, and lies about 7 km southwest of Hoorn.
The village was first mentioned in the 12th century 1420 Asthusa, and means "big (eastern) settlement".
Grost (big) was added to distinguish from Oosthuizen.
[3] Grosthuizen developed as a peat excavation settlement in the 13th century.