In the lists below, next to each unit name are the estimated unit numbers in (backets) , followed by a guess-timated pike:shot ratio for infantry units.
Scots Royalist Army
Lt General James Graham, 1st Marquis of Montrose
Maj General Alasdair MacColla, "The Devastator"
Macolla's Lifeguard (140), 0:1
Irish Mercenaries (600), 1:2
Gordon of Monymore's Regiment (300), 2:3
Strathbogie Regiment (400), 2:3
Lord Gordon's Horse (200)
Viscount Aboyne's Horse (400/200)
Scots Government Army
General Sir John Hurry
Campbell of Lawer's Regt (400), 2:3
Earl of Loudon's (Lord Chancellor's) Regt (400), 2:3
Earl of Lothian's Regt (400), 2:3
Earl of Findlater's Regt (300), 1:1
Detachment from Buchanan's Regt (200), 1:1
Northen Levies (400), 1:1
Earl of Seaforth's Levies (500), 1:1
Earl of Sutherland's Levies (500), 1:1
Campbell of Lawers' Horse (30)
Major Drummond's Horse (100)
Sir James Halkett's Horse (160)
There is some uncertainty as to the exact numbers present in both armies at Auldearn. It is generally accepted that the Covenanters outnumbered the Royalists by about 3:2, however the overall quality and experience level of the Royalist army was better that the Government force, in which over half the infantry were poorly trained, recently raised levies. The Royalists also had recently acquired a formidable cavalry wing with the defection of Huntly's sons to the Royalist cause after Montrose's previous victory over the Covenanters at Inverlochy. The exact numbers in the 'Gordon Horse' is highly uncertain and could range from 200 to 600. Reid's interpretation of the primary sources proposes a whopping 600; 200 under Lord Gordon, and 400 under his brother, the Viscount Aboyne.