'JC' was the designation of Allied convoys (together with a numerical and sometimes a literal suffix) plying the route from Colombo, Ceylon, to Calcutta and other Indian ports, and as such reciprocals of the 'CJ' series (July 1942/March 1945).

The first of the 124 such convoys was JC.2 of 26/31 July 1942 from Colombo to Vizagpatnam with the 5,881-ton British Custodian, 2,183-ton British Haiching, 3,000-ton British Shengking, 6,405-ton British Tasmania and 3,120-ton British Warina escorted by the British corvette Aster, Indian sloop Jumna and Indian auxiliary patrol vessel Sonavati. The last was JC.72 of 18/20 March 1945 from Colombo to Madras with just the 11,080-ton British Dilwara.