| Daikoku Island | |
| Native Name: | 大黒島 |
| Location: | Pacific coast of eastern Hokkaidō |
| Coordinates: | 42.9503°N 144.8691°W |
| Area Km2: | 1.07 |
| Area Footnotes: | [1] |
| Length Km: | 1.8 |
| Length Footnotes: | [2] |
| Width M: | 700 |
| Coastline Km: | 6.1 |
| Elevation M: | 108 |
| Country: | Japan |
| Country Admin Divisions Title: | Prefecture |
| Country Admin Divisions: | Hokkaido |
| Country Admin Divisions Title 1: | Subprefecture |
| Country Admin Divisions 1: | Kushiro Subprefecture |
| Country Admin Divisions Title 2: | District |
| Country Admin Divisions 2: | Akkeshi District |
| Country Admin Divisions Title 3: | Village |
| Country Admin Divisions 3: | Akkeshi |
| Population: | uninhabited |
is an uninhabited island in Akkeshi, Hokkaidō, Japan. Together with the smaller island of to the north, it forms a natural breakwater at the entrance to .[3] At the southwest tip of the island at an elevation of approximately 105 metres is, which began operations on 25 November 1890.[3] [4] Of the island's 107 hectares, 64 are owned by the state, 42 by the municipality, and one is in private hands.[2]
The island forms part of Akkeshi Prefectural Natural Park and its entire area of 107 hectares is a Special Wildlife Protection Area.[1] [5] It provides an important breeding ground for seabirds, in particular several hundred thousand Leach's storm petrel,[2] as well as the tufted puffin, Japanese cormorant, pelagic cormorant, spectacled guillemot, slaty-backed gull, and rhinoceros auklet.[2] [6] [3] Twelve hectares of the breeding grounds have been designated a Natural Monument.[6] The island has been recognised as an Important Bird Area (IBA) by BirdLife International for its seabird colonies.[7]
Also found on the island are the grey-sided vole and harbour seal.[2] [8] Trees include the green alder, painted maple, and Erman's birch; other plants, Sakhalin knotweed and Parasenecio hastatus.[2]