'Erasmus' was a British army and navy deception operation based on a false order of battle and intended to cover the transfer of troops from Africa to Ceylon, to exaggerate the number of men being moved, and to deter the Japanese from attempting to use submarines in order to attack the troop transport convoys (February/August 1943).

Part of 'Bardstown', the undertaking was schemed as the means of transferring two brigades of Major General C. C. Fowkes’s 11^th (East Africa) Division from Mombasa to Trincomalee by suggesting that the brigades were in fact destined for the Middle East. In the event the Royal Navy decided that the Japanese submarine arm represented a threat so small that 'Erasmus' was not necessary in its initially conceived form, and it ended as a 'conventional' order of battle deception to persuade the Japanese that an entire division was being moved to India.