'TH' was the designation of Allied convoys (together with a numerical suffix) plying the route from Trinidad to Halifax, Nova Scotia, and as such reciprocals of the 'HT' series (June/July 1942).

Two precursor convoys were TH.NN1 of 6/17 May and TH.NN2 of 18/28 May. The first true convoy of this short four-convoy series was TH.2 of 4/15 June 1942 with the 6,840-ton British British Governor, 5,343-ton US Cities Service Fuel, 5,850-ton Panamanian Clio, 7,264-ton British El Grillo, 8,252-ton Dutch Murena, 10,169-ton Panamanian Stanvac Cape Town and 8,906-ton US Tide Water Associated, and the last was TH.4 of 4/18 July with the 9,430-ton Norwegian Alar, 9,976-ton Norwegian Britamer, 8,268-ton Norwegian Fenja, 8,267-ton Norwegian Polycastle and 7,791-ton US Wallace E. Pratt.