The 'Blitz on Swansea' was the German heavy and sustained bombing of Swansea on the southern coast of Wales (19/21 February 1941).

Totals 230 people were killed and 397 injured. Swansea had been selected by the Germans as a legitimate strategic target as a consequence of its importance as a port and docks and the presence of an oil refinery just beyond it, and its destruction was a major element in the German effort to use strategic bombing in order to cripple the coal export capability of southern Wales and to demoralise the civilian population and the emergency services.

With the passing of the Air Raid Precaution Act of 1937, Swansea council became responsible for instigating civil defence measures to protect the local population of 167,000 people and, as a result, the local authority looked into the possibility of constructing communal air raid shelters and setting up the necessary rescue and fire services. As the threat of war with Germany increased toward the end of the 1930s, Swansea council had built over 500 communal air raid shelters as well as provided the materials for building Anderson shelters in domestic premises. With the outbreak of war in September 1939, the pace of shelter provision shelters increased further, and to complement the communal shelters that had already been built, the council requisitioned cellars and basements as makeshift shelters.

Those with gardens often built Anderson shelters in which to take refuge. However, not everyone was so fortunate, and others had to use crowded public shelters. Late 1940 saw the introduction of the Morrison shelters, which was little more than a steel table under which the members of a family could hide inside the house. Others made a nightly trek to nearby rural areas, sleeping in tents, cars or even on the beach.

The first air raid on Swansea began at 03.30 on 27 June 1940. An initial marker flare was dropped by a Luftwaffe aeroplane, and the following bombers dropped high explosives to the east of the city centre in the Danygraig residential area. The raid was relatively light, with no casualties reported to the ARP controllers. A number of unexploded bombs were discovered in the Kilvey Hill area.

Through the rest of 1940, Swansea was targeted by single and small groups of German bombers. There were several small-scale raids in January 1941, but the worst bombing period occurred over three nights on 19, 20 and 21 February 1941. This period, which became known as the Three Nights' Blitz, started at 19.30 on 19 February. On this first night, the building housing both the headquarters of the 79^th (Hertfordshire Yeomanry) Heavy Anti-Aircraft Regiment, Royal Artillery and the Gun Operations Room in Swansea were destroyed by a bomb. Two officers and five other ranks were killed or died of wounds, but the guns continued firing under local control, and communications were maintained.

On the evening of 21 February, there was confusion between the Sector Operations Room at RAF Pembrey and the temporary Swansea GOR. This resulted in the guns ceasing fire between 20.20 and 21.10, and as no night-fighters arrived, the town centre was left unprotected. Although some raiders were shot down once the restriction had been lifted, the centre of Swansea was devastated, and fires and delayed-action bombs destroyed communications and slowed recovery operations.

By the time the all-clear siren sounded after three days, major parts of the Brynhyfryd, Townhill and Manselton areas had been destroyed, and 230 people were dead and 409 injured. Moreover, 7,000 people had lost their homes. The city centre suffered direct hits that started major conflagrations which destroyed many commercial premises, including the Ben Evans department store and the Victorian market.

Over the three nights of the blitz, a total of nearly 14 hours of German activity were recorded, and it has been estimated that 1,273 high explosive bombs and 56,000 incendiary bombs were dropped. An area of about 41 acres (16.59 hectares) was targeted, with 857 properties destroyed and 11,000 damaged. To raise local morale following the blitz, King George VI and Queen Elizabeth, as well as the prime minister, Winston Churchill, visited Swansea.

Swansea was the target for several more raids, of which the last was recorded on 16 February 1943.