Insh Marshes are an area of floodplain of the River Spey between Kingussie and Kincraig in Badenoch and Strathspey, Highland, Scotland.

[4] They lie at altitude of approximately 240 to 220 m above sea level, and form one of the largest areas of floodplain mire and fen vegetation in Scotland.

7 km2 of the area is owned and managed by the Royal Society for the Protection of Birds (RSPB), and forms a national nature reserve.

Other notable invertebrate species present include the aquatic beetle Donacia aquatica, the fly Tipula marginella, the horse-fly Hybomitra lurida and the snipe-fly Thereva inornata.

[8] In October 2014, a species of insect called Molanna angustata, a type of caddisfly that inhabits Wales and England up to the Lake District and Yorkshire was identified here.