Events from the year 1943 in the United Kingdom. The year was dominated by the Second World War.

• Monarch – George VI
• Prime Minister – Winston Churchill (Coalition)

• 1 January
  • Total ban on civilians travelling to the Isle of Wight (continues until 25 August 1944).
  • Utility furniture first becomes available.^[1]
• 14 January – to counter a "serious increase" in U-boat operations the Royal Air Force switches its bombing campaign from industrial targets to U-boat bases in France attacking Lorient and Cherbourg-Octeville.
• 17 January – anti-aircraft shrapnel shells kill 23 people and injure 60 during a raid on London by 118 planes; six are reported losses.
• 20 January – Sandhurst Road School Disaster: a bomb kills 38 children and 6 teachers at a school in Catford, south-east London.
• 23 January – World War II: British forces capture Tripoli from the Nazis.^[2]
• 11 February – in the Midlothian and Peebles Northern by-election, the radical socialist Common Wealth Party candidate Tom Wintringham comes close to winning the seat.
• 13 February – Nuffield Foundation established by William Morris, 1st Viscount Nuffield.^[2]
• 3 March – panic at the sound of new anti-aircraft rockets leads to a crush at Bethnal Green tube station in East London, killing 183 people.^[3]
• 4–12 March – "Exercise Spartan", a major rehearsal for next year's Allied Invasion of Normandy, is staged across southern England.
• 5 March – the Gloster Meteor, the first operational military jet aircraft for the Allies, has its first test flight, at RAF Cranwell in Lincolnshire.
• 14 March – submarine HMS Thunderbolt is sunk off Sicily by an Italian corvette, the second time this vessel has been lost with all hands.^[4][5]
• 17 March – last church service in the village of Derwent, Derbyshire, before it is demolished (together with Ashopton) for construction of Ladybower Reservoir.^[6]
• 27 March – Royal Navy escort carrier HMS Dasher (D37) is destroyed by an accidental explosion in the Firth of Clyde, killing 379 of the crew of 528.
• 13 April – release of the Ministry of Information film Desert Victory, which will win this year's Academy Award for Best Documentary Feature.
• 21 April – worst bombing of Aberdeen.
• 7 May – capture of Tunis ends the campaign in North Africa.^[3]
• 16–17 May – Operation Chastise (the 'Dambuster Raid') takes place: No. 617 Squadron RAF use bouncing bombs to breach German dams in the Ruhr Valley.
• 19 May – Winston Churchill addresses a joint session of the United States Congress.
• 1 June – BOAC Flight 777, a DC-3 on a scheduled passenger flight, is shot down over the Bay of Biscay by eight German Junkers Ju 88s; all 17 persons aboard perish, including the actor Leslie Howard.
• 24/25 June – Battle of Bamber Bridge: trouble flares between black American soldiers and white military police stationed in the Lancashire town; one black soldier is killed.^[7][8][9]
• 9 July–17 August – World War II: Allied invasion of Sicily.
• 5 August – North of Scotland Hydro-Electric Board established by Act of Parliament.^[10]
• 3–16 September – World War II: Allied invasion of Italy: Allied forces under General Sir Bernard Montgomery land in mainland Italy. On 16 September, the Salerno Mutiny occurs when soldiers of the British Army's X Corps refuse postings to new units.
• 15 September – first examples of standard cottages for farmworkers are completed, at Hildenborough, Kent.^[11]
• 26 September – trouble flares between black American soldiers and white military police stationed in Launceston, Cornwall; shots are fired.^[12]
• 11 November
  • Regency Act is passed allowing Counsellors of State absent during the Sovereign's absence not to be listed among the appointments; and that the heir-apparent or presumptive to the Throne need only to be eighteen to be a Counsellor.^[13]
  • Total evacuation of an area near Portmahomack in Scotland begins, to make way for rehearsal of the Normandy Landings.^[14]
• 16 November – total evacuation of the village of Imber on Salisbury Plain concludes, to make way for U.S. troop training; total evacuation of part of the South Hams of Devon begins, to make way for rehearsal of the Normandy Landings.^[15]
• 22–26 November – Cairo Conference ("Sextant"): Prime Minister of the United Kingdom Winston Churchill, President of the United States Franklin D. Roosevelt and Chairman of the National Government of China Chiang Kai-shek meet at Cairo in Egypt to discuss ways to defeat Japan in the Pacific War.
• 26 November – World War II: British troopship HMT Rohna is sunk off the north African coast by a Luftwaffe Henschel Hs 293 radio controlled glide bomb killing 1015.^[16][17]
• 2 December
  • First "Bevin Boys" selected from conscripts to work in the coal mines.^[18]
  • Pigeons White Vision, Winkie and Tyke become the first recipients of the Dickin Medal, instituted to honour the work of animals in war.^[19]
• 26 December – World War II: Battle of the North Cape – German battleship Scharnhorst is torpedoed and sunk in a night action north of the Arctic Circle by Royal Navy battleship HMS Duke of York and her escorts with the loss of all but 36 of the German crew of 1,943;^[20][21] this is the war's last action between big-gun capital ships of Britain and Germany.
• December – construction of prototype Mark I Colossus computer, the world's first totally electronic programmable computing device, at the Post Office Research Station, Dollis Hill, to assist in cryptanalysis at Bletchley Park, is completed.^[22]
• Undated – Anne Loughlin becomes the first trades unionist appointed DBE and the first female President of the Trades Union Congress.

• Nigel Balchin's novel The Small Back Room.
• T. S. Eliot's poetry Four Quartets.
• David Lack's study The Life of the Robin.
• C. S. Lewis' novel Perelandra.
• Nikolaus Pevsner's book An Outline of European Architecture.
• Malcolm Saville's children's novel Mystery at Witchend, first in The Lone Pine series.

• List of British films of 1943
• Military history of the United Kingdom during World War II