'UC' was the designation of Allied fast convoys (together with a numerical and sometimes a literal suffix) plying the route from Liverpool in the UK to the Caribbean (first five) and New York, and as such reciprocals of the 'CU' series (February 1943/June 1945).

The 71 convoys of the series comprised 14-kt tankers and merchant ships sailing in ballast. Some 17 tankers departed Liverpool on 15 February 1943 as the UC.1 convoy together with 15 fast freighters escorted by four modern US destroyers (Charles F. Hughes, Hilary P. Jones, Lansdale and Madison) and the British 42^nd Escort Group (sloops Folkestone, Gorleston and Weston, frigates Exe and Ness, and old destroyer Bradford).

This was the only convoy of the 'UC' series successfully attacked by U-boats. On 23 February the 8,882-ton British tanker Athelprincess was sunk by Kapitänleutnant Siegfried Hesemann’s U-186, and Kapitänleutnant Günter Poser’s U-202 sank the 7,989-ton US tanker Esso Baton Rouge and damaged the 9,811-ton British tanker Empire Norseman, 8,482-ton British tanker British Fortitude and 8,252-ton Dutch tanker Murena. Empire Norseman was later sunk by Kapitänleutnant Günther Krech’s U-558, but the other two ships reached Guantánamo. The surviving tankers arrived in Curaçao on 6 March and the freighters proceeded to South African and Indian Ocean destinations.

Other sailings direct to Curaçao were UC.2 in April, UC.3 in June, UC.3A in July, and UC.4 in September. UC.5 departed Liverpool on 29 October 1943 as the first of the series routed to New York. UC.37 reached New York on 23 September 1944. Most subsequent convoys of the series sailed in two sections: UC.38A departed Liverpool on 19 September 1944, and UC.38B four days later. UC.71 departed Liverpool on 3 June 1945, for dispersal on 4 June, as the last of the series.