| Coordinates: | 57.41°N -7.28°W |
| Location Map: | Scotland Outer Hebrides |
| Caption: | Grimsay shown within the Outer Hebrides |
| Official Name: | Grimsay |
| Gridreference: | NF831473 |
| Celtic Name: | Griomasaigh |
| Norse Name: | Grímsey |
| Meaning Of Name: | "Grim's island", from Norse |
| Area: | 1172NaN2[1] |
| Area Rank: | 142 |
| Highest Elevation: | 200NaN0 |
| Population: | 20 |
| Population Density: | 17 people/km2 |
| Population Rank: | 65 |
| Local Authority: | Na h-Eileanan Siar |
Grimsay, south east of Benbecula is a tidal island of the Outer Hebrides. It is connected to Benbecula by a causeway which carries the B891. In the 2001 census, Grimsay had a population of 19,[1] and 20 in 2011.
An extension to the B891 now connects Grimsay to Eilean na Cille to the south east via a causeway. The road was built at a cost of £1,800 to service the pier at Peter's Port, which was constructed in 1896 at cost of £2,000 – although the anchorage is awkward and use by people without local knowledge is discouraged.[2]