| Official Name: | Maarssen |
| Flag Size: | 120x100px |
| Mapsize: | 250px |
| Subdivision Type: | Country |
| Subdivision Name: | Netherlands |
| Subdivision Type1: | Province |
| Subdivision Name1: | Utrecht |
| Subdivision Type2: | Municipality |
| Subdivision Name2: | Stichtse Vecht |
| Area Footnotes: | (2006) |
| Area Total Km2: | 30.86 |
| Area Land Km2: | 27.20 |
| Area Water Km2: | 3.66 |
| Population As Of: | 1 January 2007 |
| Population Note: | Source: CBS, Statline. |
| Settlement Type: | Town and former municipality |
| Population Total: | 39363 |
| Population Density Km2: | 1447 |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Coordinates: | 52.1351°N 5.0413°W |
| Website: | www.stichtsevecht.nl |
Maarssen (pronounced as /nl/) is a town in the middle of the Netherlands, in the province of Utrecht, along the river Vecht and the Amsterdam–Rhine Canal. The west of Maarssen is called Maarssen-Broek[1] whereas the east is called Maarssen-Dorp. Both put together and joined by other small towns around provide the area of Maarssen.
On 1 January 2011 Maarssen merged with the councils of Breukelen and Loenen to become Stichtse Vecht.
The former municipality of Maarssen consisted of the following cities, towns, villages and/or districts: