'Ajax' was a British unrealised plan for a naval-led operation against positions in German-occupied Norway (September/November 1941).

Resulting in part from Soviet demands for the urgent opening of a second front in western Europe and thus the likely easing of the situation on the Eastern Front by forcing the Germans to redeploy a large number of their divisions to the west, and in part from Prime Minister Winston Churchill’s fascination with launching a major operation on the northern flank of German-occupied Europe, 'Ajax' was to have been centred on the establishment of a beach-head in west central Norway by means of a landing at Trondheim supported by large-scale offensive operations within central Norway by the local resistance forces. The British chiefs-of-staff were adamantly opposed to the concept, which smacked of a revival of the abortive and unrealistic 'Hammer' of 1940, and which they also felt would expose invaluable British land forces, without the possibility of realistic support from the UK, in an undertaking of no real operational or strategic value.