Liverpool formed part of the 7th Cruiser Squadron, becoming one of nine cruisers that could be fielded by the Mediterranean Fleet shortly after Fascist Italy entered the war.
She first encountered Italian vessels off the coast of Libya on 12 June while shelling positions near Tobruk with Gloucester and four destroyers.
The cruisers attacked five vessels, including the obsolete armoured cruiser San Giorgio, and sank the minesweeper Giovanni Berta.
On 28 June, a British Short Sunderland patrol aircraft detected three Italian destroyers west of Zante.
The 7th Cruiser Squadron was at sea in support of convoy Operation MA.3 when it altered course to engage the destroyers.
Liverpool sighted them 60 miles (97 km) south-west of Cape Matapan at 18:30 and opened fire three minutes later.
The ensuing action, carried out at a minimum range of about 14,000 yards (8.0 mi), resulted in the destruction of the Italian Espero The two surviving destroyers reached Benghazi with their supplies.
Liverpool took light damage in the engagement.
Ammunition had been rapidly depleted by the cruiser squadron.
By the close of the action, Liverpool's crew had almost expended the contents of her shellrooms, reporting that each gun had 40 shells remaining.
The Admiralty criticised the squadron's expenditure of some 5,000 6-inch (150 mm) rounds, which Admiral Andrew Cunningham, commander-in-chief of the Mediterranean Fleet, attributed to its inexperience and his insistence on confronting the Italian warships before nightfall.
Nevertheless, the use of such a large volume of shells caused the cancellation of MA.3, which had encompassed two convoys from the besieged island of Malta.

The Mediterranean Fleet followed MA.3 with Operation MA.5 in early July.
During the course of the deployment, Admiral Cunningham received reports of a large formation of Italian warships and changed course towards Taranto to intercept.
On 9 July, the fleets encountered each other off Calabria, in the first major battle between the Allied and Italian navies in the Mediterranean theatre.
Liverpool and fellow cruiser Neptune commenced firing at 15:22, eight minutes after Italian cruisers started their barrage at a range of 23,600 yards (13.4 mi).
After a continuous exchange of fire, the battleship Warspite struck the Italian battleship Giulio Cesare at 16:00, inducing the Italian fleet to disengage from the battle.
Italian aircraft attacked Liverpool with bombs on 12 July while she was returning to Alexandria, Egypt, causing fatalities and wounding three, including the cruiser's commander.
Later in July, Liverpool escorted convoy AN.2 from Egypt on its way to Greek ports in the Aegean and the southward-convoy AS.2 from the Aegean.
The latter convoy came under substantial attack by Italian aircraft on the 29th; Liverpool was the only vessel hit when an unexploded bomb penetrated two decks, killing a rating.
 The casualty was Stoker First Class Patrick Leslie Harney, aged 32, from Stalybridge, Cheshire.

When the Mediterranean Light Forces restructured in August, Liverpool was switched to the 3rd Cruiser Squadron, grouped with Liverpool and Kent under the command of Rear-Admiral Edward de Faye Renouf.
On 28 September, as part of Operation MB.5, Liverpool and Liverpool proceeded to Malta, transporting reinforcements, airmen, and RAF provisions.
The cruisers—briefly protected by a force consisting of the battleships Valiant and Warspite, aircraft carrier Illustrious with her aircraft, cruisers Orion, York and the Australian HMAS Sydney, and 11 destroyers—came under repeated aerial attack.
 Both cruisers later detached from the naval force and reached the island on the 30th.

The fleet again put to sea on 8 October with the intention of supporting Malta convoy MF.3 and the Alexandria-bound convoy MF.4, while seeking to engineer an encounter with the main assets of the Italian Navy.
Although Admiral Cunningham did not realise his latter objective, which was limited to an engagement with Italian destroyers, the convoys reached their respective destinations.
Illustrious then conducted aerial
Liverpool formed part of the 7th Cruiser Squadron, becoming one of nine cruisers that could be fielded by the Mediterranean Fleet shortly after Fascist Italy entered the war. She first encountered Italian vessels off the coast of Libya on 12 June while shelling positions near Tobruk with Gloucester and four destroyers. The cruisers attacked five vessels, including the obsolete armoured cruiser San Giorgio, and sank the minesweeper Giovanni Berta. On 28 June, a British Short Sunderland patrol aircraft detected three Italian destroyers west of Zante. The 7th Cruiser Squadron was at sea in support of convoy Operation MA.3 when it altered course to engage the destroyers. Liverpool sighted them 60 miles (97 km) south-west of Cape Matapan at 18:30 and opened fire three minutes later. The ensuing action, carried out at a minimum range of about 14,000 yards (8.0 mi), resulted in the destruction of the Italian Espero The two surviving destroyers reached Benghazi with their supplies. Liverpool took light damage in the engagement. Ammunition had been rapidly depleted by the cruiser squadron. By the close of the action, Liverpool's crew had almost expended the contents of her shellrooms, reporting that each gun had 40 shells remaining. The Admiralty criticised the squadron's expenditure of some 5,000 6-inch (150 mm) rounds, which Admiral Andrew Cunningham, commander-in-chief of the Mediterranean Fleet, attributed to its inexperience and his insistence on confronting the Italian warships before nightfall. Nevertheless, the use of such a large volume of shells caused the cancellation of MA.3, which had encompassed two convoys from the besieged island of Malta.
The Mediterranean Fleet followed MA.3 with Operation MA.5 in early July. During the course of the deployment, Admiral Cunningham received reports of a large formation of Italian warships and changed course towards Taranto to intercept. On 9 July, the fleets encountered each other off Calabria, in the first major battle between the Allied and Italian navies in the Mediterranean theatre. Liverpool and fellow cruiser Neptune commenced firing at 15:22, eight minutes after Italian cruisers started their barrage at a range of 23,600 yards (13.4 mi). After a continuous exchange of fire, the battleship Warspite struck the Italian battleship Giulio Cesare at 16:00, inducing the Italian fleet to disengage from the battle. Italian aircraft attacked Liverpool with bombs on 12 July while she was returning to Alexandria, Egypt, causing fatalities and wounding three, including the cruiser's commander. Later in July, Liverpool escorted convoy AN.2 from Egypt on its way to Greek ports in the Aegean and the southward-convoy AS.2 from the Aegean. The latter convoy came under substantial attack by Italian aircraft on the 29th; Liverpool was the only vessel hit when an unexploded bomb penetrated two decks, killing a rating.  The casualty was Stoker First Class Patrick Leslie Harney, aged 32, from Stalybridge, Cheshire.
When the Mediterranean Light Forces restructured in August, Liverpool was switched to the 3rd Cruiser Squadron, grouped with Liverpool and Kent under the command of Rear-Admiral Edward de Faye Renouf. On 28 September, as part of Operation MB.5, Liverpool and Liverpool proceeded to Malta, transporting reinforcements, airmen, and RAF provisions. The cruisers—briefly protected by a force consisting of the battleships Valiant and Warspite, aircraft carrier Illustrious with her aircraft, cruisers Orion, York and the Australian HMAS Sydney, and 11 destroyers—came under repeated aerial attack.  Both cruisers later detached from the naval force and reached the island on the 30th.
The fleet again put to sea on 8 October with the intention of supporting Malta convoy MF.3 and the Alexandria-bound convoy MF.4, while seeking to engineer an encounter with the main assets of the Italian Navy. Although Admiral Cunningham did not realise his latter objective, which was limited to an engagement with Italian destroyers, the convoys reached their respective destinations. Illustrious then conducted aerial
HMS Liverpool (C11)