'BT' (iv) was the designation of Allied convoys (together with a numerical suffix) plying the route from Brisbane to Townsville, Australia (August 1942/May 1943).

The first of these 'Brisbane to Townsville' convoys was BT.1 of 28/31 August 1942 with the 3,188-ton British Anshun, 4,088-ton British Montoro, 6,021-ton US Sea Witch, 5,084-ton Dutch Swartenhondt, and 4,286-ton British Taroona, and the last was BT.61 of 21/24 May 1943 with the 1,279-ton Dutch Balikpapan, 7,176-ton US Henry Dearborn, 2,075-ton Dutch Pahud, 4,873-ton British Suva, 3,234-ton Dutch Van Spilbergen, and 7,176-ton US William Ennery Channing.