'GB' was the designation of Allied convoys (together with a numerical suffix) plying the route in the South-West Pacific Area to Milne Bay, and as such reciprocals of the 'BG' series (July 1944/May 1945).

The first of the series was GB.1 of 15/17 July 1944 from Humboldt to Langemark Bay with the 7,176-ton US Albert A. Robinson, 2,071-ton Dutch Janssens, 7,176-ton US Robert Stuart, 7,176-ton US Tecumseh, 7,191-ton US Thomas Nelson, and 2,464-ton Dutch Van der Lijn. The last of the series was GB.764 of 25/29 May 1945 from Morotai to Hollandia with the 7,176-ton US Peter Cartwright and 7,176-ton US Richard Harding Davis.