| Nieuwkoop | |
| Settlement Type: | Municipality |
| Flag Size: | 100x67px |
| Map Alt: | Highlighted position of Nieuwkoop in a municipal map of South Holland |
| Coordinates: | 52.1833°N 50°W |
| Subdivision Type: | Country |
| Subdivision Name: | Netherlands |
| Subdivision Type1: | Province |
| Subdivision Name1: | South Holland |
| Government Footnotes: | [1] |
| Governing Body: | Municipal council |
| Leader Party: | CDA |
| Leader Title: | Mayor |
| Leader Name: | Robbert-Jan van Duijn |
| Unit Pref: | Metric |
| Elevation Footnotes: | [2] |
| Elevation M: | -5 |
| Timezone1: | CET |
| Utc Offset1: | +1 |
| Timezone1 Dst: | CEST |
| Utc Offset1 Dst: | +2 |
| Postal Code Type: | Postcode |
| Postal Code: | 2420–2441, 2460–2461, 3651–3653 |
| Area Code Type: | Area code |
| Area Code: | 0172, 0297 |
Nieuwkoop (in Dutch; Flemish pronounced as /ˈniukoːp/) is a town and municipality in the western Netherlands, in the province of South Holland. The municipality was enlarged on 1 January 2007, through the amalgamation of Liemeer and Ter Aar. The municipality now covers an area of NaNNieuwkoop}} of which NaNNieuwkoop}} is water. Its population was in .
On May 3, 2008, the Dutch newspaper Algemeen Dagblad published an article which stated that Nieuwkoop is the safest municipality of the Netherlands.
The municipality of Nieuwkoop includes the following communities:
The oldest part of Nieuwkoop are the buildings along the Nieuwkoopse Plassen (Nieuwkoop's Ponds), many of which are completely surrounded by water and accessible over individual bridges to the main road. The Nieuwkoopse Plassen are shallow lakes that were dug for peat harvesting in the 16th century and are now designated as a natural monument. New neighborhoods north-west of the main road are built after World War II.