'AT' (i) was the designation of Allied convoys (together with a numerical suffix) plying the route from Alexandria to Tobruk on the northern coast of Africa, and as such reciprocals of the 'TA' series (November 1941/June 1942).

The first of these 46 convoys was AT.1/M of 30 November/2 December 1941 with five escort vessels in the form of the Australian destroyer Yarra, Free Greek destroyer Kondouriotis, British escort destroyers Avon Vale and Heythrop, and British sloop Flamingo. The last was AT.49/M of 9/11 June 1942 with the 4,681-ton Norwegian merchant vessel Athene, 5,917-ton British fleet oiler Brambleleaf and 2,073-ton British merchant vessel Havre.