The 'Blitz on Southampton' was the German heavy bombing of Southampton (1940/42).

Southampton was a strategic bombing target for the Luftwaffe as it contained both important docks with associated business premises and factories and the Supermarine factory building Spitfire single-engined fighters in Woolston. Being a large port city on the southern coast of England, Southampton lay within easy reach of German airfields in defeated France.

During the war, 57 attacks were flown against the city, in which more than 1,500 air raid warnings were issued. According to the Air Raid Precautions department, about 2,300 bombs were dropped, this constituting more than 470 tons of high explosives. In addition, a total of 30,000 or more incendiary devices was dropped on the city, in which nearly 45,000 buildings were damaged or destroyed.

The Supermarine factory in Woolston, where Spitfire warplanes were manufactured, was a significant target in the city. On 24 and 26 September 1940, the Luftwaffe bombed the riverside factory in two day-time raids. Much of the factory was destroyed and 110 people were killed. The Northam gas works was also targeted on 26 September and 11 workers were killed in the raid.

A daylight raid on 6 November 1940 targeted the city’s Civic Centre. Reichsmarschall Hermann Göring, commander-in-chief of the Luftwaffe, had remarked that the Civic Centre appeared like a 'piece of cake' from the air, and that he was going to 'cut himself a slice'. During the raid that eventuated, 12 bombs were dropped, including a 551-lb (250-kg) weapon which was a direct hit on the Civic Centre: the bomb penetrated to the lower floors of the art gallery, killing 35 people including 15 children who were having an art lesson in the basement.

Of the 57 air raids, by far the worst were that of 23 and 30 November and 1 December 1940, and in its these attacks which are generally known as the 'Blitz on Southampton'. Starting at 18.15 and extending to 00.00 on the evening of 23 November, the rai8d killed 77 people an injured more than 300, and it was the Civic Centre which bore much of the brunt of the attack. The raid ruined the city’s water supply and many of the fires had to be left to burn themselves out. There were reports that the glow of the firestorm in Southampton could be seen from as far away as Cherbourg on the northern coast of France, and the German propaganda machine declared that the city had been left a smoking ruin.

One week later, 120 German bombers returned for another six-hour attack on the evening of 30 November. The 800 bombs dropped on the city left 137 dead, 96 of them killed in their air raid shelters. Major buildings including the Pirelli Cable Works, the Daily Echo newspaper building and the General Motors factory were severely damaged or destroyed. All Saints', Holyrood and St Mary’s churches, were destroyed, but St Michael’s church escaped with only minor damage, allegedly because the spire was used by the German bombers as a landmark and their pilots were ordered not to hit it. Altogether, Southampton lost seven churches during the blitz, as well as the Audit House, the Ordnance Survey offices and many shops, factories and homes.

The last casualties of air raids in the city were those resulting from a small raid on the suburbs of the city in May 1941 and on 8 July 1941 in the area of Victory Crescent, Millbrook, killing three people. The last major raid of more than 50 bombers took place in June 1942. There were occasional tip-and-run raids by German fighter-bombers, and in the middle of July 1944 two V-1 flying bombs were the last items of German ordnance to fall on the city.