Muckle Green Holm is an uninhabited island in the North Isles of the Orkney archipelago in Scotland.

It is roughly 28 hectares (0.11 sq mi) in extent and rises to 28 metres (92 ft) above sea level, the summit having a triangulation pillar.

Eastward is a strait called Fall of Warness between Muckle Green Holm and the much larger island of Eday.

Muckle Green Holm has a great cormorant colony and a population of European otters.

Starting in 2007,[5] the European Marine Energy Centre installed tidal power testing equipment.