Grenville-sur-la-Rouge covers a rectangular area along the shore of the Ottawa River and extends northward into the foothills of the Laurentian Mountains.

Located between the outlets of the Rouge and Calumet Rivers [fr], the peninsula's sheltered beaches, including the plage de la baie Pumpkinseed are known to birdwatchers for the variety of wading and shore birds that visit seasonally.

While Canada was still under British rule, the Grenville Canal was built by the military to bypass a series of rapids in the Ottawa River.

In April 2019, record high water levels on the Rouge River made authorities order evacuation of parts of the community as a precaution in case the Bell Falls, or Chute-Bell, hydroelectric dam collapsed.

Tourism is an important part of the local economy, with several whitewater adventure companies being established along the Rouge River.

First commercialized in the late 1970s, the Rouge River has become Quebec's most popular whitewater rafting location and is considered one of the best in North America.

The 2001 Statistics Canada census reports that the majority of Grenville-sur-la-Rouge's residents earn income from non-resource based sectors.

In the late 1960s, Alfred Joseph Casson (1892–1992) of Group of Seven fame, spent some time in what is now known as Grenville-sur-la-Rouge capturing the beautiful scenery on the lower Ottawa Valley.

Duval writes, "Near to Grenville, were Harrington, Avoca and Montebello, all ideal landscape sites offering a rich variety of topography ...