'Comet' was a British unrealised plan for the use of Major General R. E. Urquhart’s 1^st Airborne Division to land and seize crossing points over the Nederrijn river near Arnhem (September 1944).

In the plan, which was suggested by General Sir Bernard Montgomery, commander of the Allied 21^st Army Group, on 2 September, each of the 1^st Airborne Division’s three brigades, with support from Generał brygady Stanisław Sosabowski’s Polish 1^st Independent Parachute Brigade, was to take a bridge and thus speed the advance of Lieutenant General Sir Miles Dempsey’s 2^nd Army toward the northern Netherlands and into the north German plain.

The divisional headquarters, Brigadier P. H. W. Hicks’s 1^st Airlanding Brigade and the Polish 1^st Independent Parachute Brigade were to land at Nijmegen, Brigadier G. W. Lathbury’s 1^st Parachute Brigade was to land at Arnhem, and Brigadier J. W. Hackett’s 4^th Parachute Brigade was to land at Grave. Several days of poor weather and his concerns over increasing levels of German resistance then persuaded Montgomery to postpone the operation and then finally to cancel it on 10 September.

The plan was rapidly evolved into the definitive 'Market'.