'MG4' was a British naval gunfire bombardment of Axis positions on the island of Rhodes (12/14 August 1942).

Undertaken by the light cruiser Arethusa and the light anti-aircraft cruiser Cleopatra, supported by the destroyers Javelin, Kelvin, Sikh and Zulu, the operation was designed to distract the attention of the Axis forces from 'Pedestal'.

On 10 August Arethusa and Cleopatra had sailed with the fleet destroyers Jervis, Kelvin and Packenham, the escort destroyers Aldenham, Beaufort, Dulverton, Eridge, Hursley and Hurworth, corvette Hyacinth and auxiliary escort Antwerp to escort the MW.12 convoy of three merchant vessels from Malta through the eastern Mediterranean. On 11 August the light anti-aircraft cruisers Cleopatra and Dido and the fleet destroyers Javelin, Sikh and Zulu departed to escort a single merchant ship which had departed Haifa on the coast of Palestine and joined the MW.12 convoy.

On 12 August Arethusa and Cleopatra and three of the fleet destroyers left the convoy to carry out the diversionary gunfire bombardment of Rhodes, and then rejoined the MW.12 convoy for the rest of the passage to Alexandria, which the ships reached on 13 August.