'SU' was the designation of Allied convoys (together with a numerical and sometimes a literal suffix) plying the route from the Suez Canal, Egypt, Aden, and Colombo, Ceylon, to Australia carrying Australian troops and equipment being returned home to strengthen the defence of Australia against the threat of Japanese invasion, and as such reciprocals of the 'US' series (March 1942/January 1943).

The first of these 16 convoys was SU.1 of 1/15 March 1942 with the 8,956-ton British City of London, 10,902-ton British City of Paris, 10,926-ton British Eastern Prince, 5,108-ton British Egra, 7,006-ton British Empire Glade, 14,204-ton British Esperance Bay, 3,533-ton British Gorgon, 4,850-ton British Industria, 6,852-ton Polish Kosciuszko, 5,080-ton British Madras City, 8,890-ton British Mathura, 8,440-ton Norwegian Norden, 6,369-ton British Penrith Castle, 5,305-ton British Pundit, 6,770-ton British Silverteak, 6,373-ton British Silverwillow and 5,296-ton British Trevilley. The last convoy was SU.5A of 5/9 January 1943 from Fremantle for dispersal with five Dutch vessels in the form of the 2,075-ton Pahud, 2,065-ton Patras, 2,462-ton Reijnst, 2,071-ton Thedens and 2,147-ton Van Swoll.