| Les Collines-de-l'Outaouais | |
| Settlement Type: | Regional county municipality |
| Coordinates: | 45.55°N -127°W |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Type2: | Region |
| Subdivision Name2: | Outaouais |
| Established Title: | Effective |
| Established Date: | December 4, 1991 |
| Seat Type: | County seat |
| Seat: | Chelsea |
| Government Type: | Prefecture |
| Leader Title: | Prefect |
| Leader Name: | Marc Carriere |
| Area Total Km2: | 2,199.30 |
| Area Land Km2: | 1,912.05 |
| Population Footnotes: | [1] |
| Population Total: | 53,657 |
| Population As Of: | 2021 |
| Population Density Km2: | 28.1 |
| Population Blank1 Title: | Change 2016-2021 |
| Population Blank1: | 11% |
| Population Blank2 Title: | Dwellings |
| Population Blank2: | 24,627 |
| Timezone: | EST |
| Utc Offset: | −5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | −4 |
| Postal Code Type: | Postal code(s) |
| Area Code: | 819 |
Les Collines-de-l'Outaouais (French for "The hills of the Outaouais") is a regional county municipality in the Outaouais region of western Quebec, Canada. The region nearly encircles the City of Gatineau, which is to the south. Its administrative seat is in Chelsea, Quebec.
It was created in January 1991 when the Communauté régionale de l'Outaouais (Outaouais Regional Community) was split into Les Collines-de-l'Outaouais RCM and the Communauté urbaine de l'Outaouais (Outaouais Urban Community, now City of Gatineau). The region is home to the majority of Gatineau Park. It is bisected by the Gatineau River which flows from north to south. The Ottawa River forms the southwestern boundary.
There are six subdivisions within the RCM:
Source: 2021 Census [1]
Highways and numbered routes that run through the municipality, including external routes that start or finish at the county border:[2]