The Argyll Group is a thick sequence of metamorphosed Neoproterozoic sedimentary rocks that outcrop across the Central Highlands of Scotland, east of the Great Glen, as well as appearing in the north of Ireland.

It is a subdivision of the Dalradian Supergroup and is itself divided into four units; from oldest to youngest these are the Islay, Easdale, Crinan and Tayvallich subgroups.

Extending between Jura, Knapdale and the Moray Firth coast, the unit can reach to 3 km thick.

Their base is characterised by a coarse quartzite in Argyll, otherwise it is formed from pelites, semipelites and psammites.

[4] The lithology of this subgroup varies across Scotland but is dominantly limestone though this is replaced in the east by psammite and quartzite.