| Bear Brook | |
| Pushpin Map: | New Hampshire#USA |
| Pushpin Map Size: | 200 px |
| Subdivision Type1: | Country |
| Subdivision Name1: | United States |
| Subdivision Type2: | State |
| Subdivision Name2: | New Hampshire |
| Subdivision Type3: | Counties |
| Subdivision Name3: | Rockingham, Merrimack |
| Subdivision Type4: | Towns |
| Subdivision Name4: | Candia, Hooksett, Deerfield, Allenstown |
| Length: | 10miles |
| Source1: | Hall Mountain Marsh |
| Source1 Location: | Candia, Rockingham County |
| Source1 Coordinates: | 43.0972°N -71.3517°W |
| Source1 Elevation: | 675feet |
| Mouth: | Suncook River |
| Mouth Location: | Allenstown, Merrimack County |
| Mouth Coordinates: | 43.1714°N -71.3947°W |
| Mouth Elevation: | 285feet |
| Tributaries Left: | Catamount Brook |
| Tributaries Right: | Pease Brook, Little Bear Brook |
Bear Brook is a 10adj=midNaNadj=mid[1] stream located in central New Hampshire in the United States. It is a tributary of the Suncook River, part of the Merrimack River (and therefore Gulf of Maine) watershed. Its entire course is within Bear Brook State Park.
Bear Brook begins at the outlet of Hall Mountain Marsh near the four-corner intersection of the towns of Allenstown, Deerfield, Candia, and Hooksett. The brook descends to the north, through Deerfield, then turns west and reenters Allenstown. Nearing Deerfield Road, the brook is impounded by Catamount Pond, with a state park beach and picnic area. The brook flows northwest from the pond and reaches the Suncook River in less than a mile.