| Achttienhoven | |
| Settlement Type: | Hamlet |
| Native Name Lang: | nl |
| Image Map1: | Map NL - Nieuwkoop - Achttienhoven.png |
| Map Caption1: | The hamlet (dark red) and the statistical district (light green) of Achttienhoven in the municipality of Nieuwkoop. |
| Pushpin Map Caption: | Location in the Netherlands |
| Subdivision Type: | Country |
| Subdivision Name: | Netherlands |
| Subdivision Type1: | Province |
| Subdivision Name1: | South Holland |
| Subdivision Type2: | Municipality |
| Subdivision Name2: | Nieuwkoop |
| Coordinates: | 52.1467°N 4.8569°W |
| Population Total: | 140 |
| Population Density Km2: | auto |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Postal Code Type: | Postal code |
| Area Code Type: | Dialing code |
Achttienhoven is a hamlet in the Dutch province of South Holland. It is a part of the municipality of Nieuwkoop, and lies about 7 km north of Woerden.
The statistical area "Achttienhoven", which also includes the surrounding countryside, has a population of around 130.
Between 1817 and 1855, Achttienhoven was a separate municipality, sometimes called "Achttienhoven en de Bosch".
The nature reserve De Haeck lies northwest of the hamlet.