| Holbrook Island Sanctuary | |
| Map: | USA Maine |
| Map Size: | 280 |
| Relief: | 1 |
| Location: | Brooksville, Maine, United States |
| Coordinates: | 44.3633°N -68.8117°W |
| Area Acre: | 1345 |
| Elevation: | 26feet |
| Established: | 1971 |
| Administrator: | Maine Department of Agriculture, Conservation and Forestry |
| Website: | Holbrook Island Sanctuary |
Holbrook Island Sanctuary is a publicly owned nature preserve with recreational features occupying on Penobscot Bay in the town of Brooksville, Hancock County, Maine. The site includes upland forest and meadows, wetland marshes and ponds, and rocky mainland shores in addition to off-shore Holbrook Island. The state park is managed by the Maine Department of Agriculture, Conservation and Forestry.
The park was established in 1971 when Anita Harris donated to the state of the holdings she had been acquiring in Brooksville since the 1960s. In accordance with Harris's wishes, the park has been maintained in its original state with minimal modern improvements.
The park has of old trails for hiking and cross-country skiing that traverse a variety of coastal habitats. The park also offers swimming, kayaking, and fishing.