| Cockermouth River | |
| Pushpin Map: | New Hampshire#USA |
| Pushpin Map Size: | 250 px |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | New Hampshire |
| Subdivision Type3: | County |
| Subdivision Name3: | Grafton |
| Subdivision Type4: | Towns |
| Subdivision Name4: | Groton, Hebron |
| Length: | 9.5miles |
| Source1: | Province Road State Forest |
| Source1 Location: | Groton |
| Source1 Coordinates: | 43.7436°N -71.9181°W |
| Source1 Elevation: | 1500feet |
| Mouth: | Newfound Lake |
| Mouth Location: | Hebron |
| Mouth Coordinates: | 43.6928°N -71.7942°W |
| Mouth Elevation: | 588feet |
| Tributaries Left: | Wise Brook |
| Tributaries Right: | Atwell Brook, Hardy Brook |
The Cockermouth River is a 9.5adj=midNaNadj=mid[1] stream located in central New Hampshire in the United States. It is the longest tributary of Newfound Lake, part of the Pemigewasset River and ultimately Merrimack River watersheds. The river takes its name from the "Cockermouth Grant", an early name for a portion of the town of Hebron.[2]
The river begins in Province Road State Forest near the western boundary of Groton, New Hampshire, and proceeds southeast across the entire town of Groton. The river is closely paralleled by Sculptured Rocks Road, a very rough dirt road which gradually becomes more passable to automobiles as it proceeds downstream. The river passes through Sculptured Rocks Natural Area, a series of narrow, sharply carved rock formations that are a popular local swimming hole, then enters a broader valley as it passes the village center of Groton.
Continuing east, the Cockermouth River enters the town of Hebron and flows into Newfound Lake near the lake's northern end.