'MD3' (ii) was a British naval gunfire bombardment of the port of Tripoli in the Tripolitania western region of the Italian North African colony of Libya and so impede the delivery of reinforcements, equipment and supplies to the Axis forces in North Africa (20/23 April 1941).

The undertaking was undertaken by forces of Admiral Sir Andrew Cunningham’s Mediterranean Fleet immediately after their involvement in 'MD2'. The main strength of the Mediterranean Fleet operated in two groups: under Cunningham’s command, the first group comprised the battleships Barham, Valiant and Warspite, the light cruiser Gloucester and the destroyers Jaguar, Janus, Jervis and Juno, and under Vice Admiral H. D. Pridham-Wippell’s command, the second group comprised the fleet carrier Formidable, the light cruisers Ajax and Orion, the paravane-equipped destroyers Hasty, Havock and Hero, and fleet destroyers Defender, Encounter, Griffin, Havelock, Hereward, Kimberley and Kingston.

The bombardment of Tripoli was undertaken at night with the aid of flares dropped by the aircraft of Formidable, and the fire of the three battleships, four cruisers and destroyers, with the submarine Truant providing navigational assistance, inflicted considerable damage on the port, its installations and its fuel storage dump, as well as hitting six freighters (one of which sank) and the Italian torpedo boat Partenope. On the following day the 5,305-ton Italian transport ship Birmania blew up, probably as a result of the spontaneous detonation of a cargo of German aircraft bombs, resulting in considerable damage to Tripoli’s port installations and also the loss of the 3,339-ton Città di Bari with all the supplies she was carrying. The devastation reduced Tripoli’s cargo-handling capabilities from 45,000 to 15,000 tons per month for a considerable period.

As the Mediterranean Fleet retired toward Alexandria, the battleship Valiant struck a mine and was damaged, and the 6,098-ton freighter British Lord was damaged by air attack in the area to the south-west of Crete.

Cunningham’s forces regained Alexandria on 23 April.