| Official Name: | Prospect Harbor |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Maine |
| Timezone: | Eastern |
| Utc Offset: | -5 |
| Timezone Dst: | Eastern |
| Postal Code Type: | ZIP code |
| Postal Code: | 04669 |
Prospect Harbor is a bay in Gouldsboro, Maine. It is separated from Gouldsboro Bay to the northeast by Cranberry Point and from Winter Harbor to the west by the Schoodic Peninsula.
The bay is roughly 3 mi. (5 km) long and 3 mi. across (5 km) at its widest.