Grosthuizen is a hamlet in the Dutch province of North Holland. It is a part of the municipality of Koggenland, and lies about 7 km southwest of Hoorn.
Grosthuizen was a separate municipality between 1817 and 1854, when it was merged with Avenhorn.
The statistical area "Grosthuizen", which also can include the surrounding countryside, has a population of around 410.
- ^ Ad van der Meer and Onno Boonstra, "Repertorium van Nederlandse gemeenten", KNAW, 2006. 
- ^ Statistics Netherlands (CBS), Statline: Kerncijfers wijken en buurten 2003-2005. As of 1 January 2005.