'SR' (iii) was the designation of Allied convoys (together with a numerical suffix) plying the route from Freetown, Sierra Leone, to Gibraltar, and as such reciprocals of the 'RS' series (February 1943/April 1945).

The first of these 24 convoys was SR.1 of 10/23 February 1943 with the 7,266-ton British Avristan, 889-ton British British Coast, 5,038-ton Panamanian Cavalcade, 5,388-ton British Ernebank, 1,375-ton Norwegian Fana, 5,108-ton British Ger-y-Brin, 5,146-ton French Hoggar, 7,369-ton British Incomati, 8,979-ton British Marquesa, 10,172-ton US Monmouth, 6,530-ton British Rhesus and 5,922-ton Norwegian Tanafjord. The convoy was escorted by the sloop Bridgewater, corvettes Penstemon and Vetch, and armed trawlers Fandango, Inkpen and Lord Nuffield.

The last of these convoys was SR.23 of 7/12 April 1945 with the 14,134-ton Dutch Boissevain and 14,139-ton British Highland Monarch.