'Corncob' (i) was a British series of three convoy operations ('Corncob I', 'Corncob II' and 'Corncob III') between Poole on the south coast of England and the Seine Bay on the north coast of France in association with 'Neptune' (iii) and thus 'Overlord' (June 1944).

The first of these convoys, on 6/7 June, comprised 24 ships (one Dutch, one Greek, one Norwegian, one Polish, two US and 18 British), several of them intended for expenditure as 'Mulberry' blockships. The second took place on the same days but no data have survived. The third, on 7/8 June, comprised 12 ships (one Dutch, one Greek, one Norwegian, one Yugoslav, two US and five British), several of them for expenditure as 'Mulberry' blockships. The convoy also included two warships for this role, namely the obsolete British battleship Centurion and the Dutch cruiser Sumatra.